John Scott

The drive shaft can be at an angle from top to bottom or left to right. What is critical is a PARALLEL match, on the VERTICAL plane, engine and rear should be square to eachother as well. Use an angle finder, cheap at sears or other. Place on the face of the differential pinion flange mounting surface and then the rear of the transmission. You need to set angle finder just outside the output shaft, or on another flat surface such as pan, as long as it is parallel to centerline of transmission. Also easy to do with just the yokes in place before you start measuring for driveshaft length. Measure against the outside of yokes in vertical position. I prefer the machined surfaces for more accurate measuring. 85/95, 90/90, 91/89, whatever, angles should = 180 degrees. 1 or less degree, I believe is what you are looking for. Perfectly phased is ideal unless engine and trans are exactly in line on all planes. Not likely. Some consider having a slightly lower pinion angle to compensate under power, since pinion raises under torque. Most diddle with the angle of the differential. In my swap I shimmed the trans crossmemeber 1/4" to attain 0 0n my finder, use solid rear mount. Suprisingly quiet and no bad vibes at any speed. John

One of the easiest T56 swaps is the aftermarket T56 availible from your chevy dealer. Uses the T5 bellhousing with included adapter plate to rotate bell correctly. I think I used a Ford truck 3/4 master with the newer all metal T5 slaves. Also uses the T5 style speedo gear. This is the lower rated 425 lb/ft trans with the .62 6th. No silly skip shift just back up lights and reverse lock out to wire up. I've been using this set up for years behind my 383 with Centerforce dual friction gold. Also have B&M ripper short throw availible, highly recommended. GREAT trans! John

Running a small carburetor on a big engine won't necessarily cause it to run lean. I'm not saying we should run out to the garage and swap the lawnmower carb onto the Z, but for example my old 68 Delta 88 455 came with a tiny 2 bbl. You can jet a 390 cfm to run rich or lean. Performance will suffer over a matched carb and potentially you will use less gas. You might be surprised of the gas mileage the V8s with the "right" size carb and good overdrive transmission can get. Often whats best for performance is best for effeceincy. You might want to consider a vacuum secondary carburetor. They tend to be more streetable, stay in the primaries longer.

GM V6 and V8. Only vote once? Procharged 4.3V6, 383 V8.

Too often we , myself included, base our opinions on what was current the last time we researched (sometimes many years ago.) When I was shopping for transmissions the T5 wasn't holding a good reputation, even aftermarket builders usually blowing out with sticky tires and hard shifting. The JTR manual summed up the T5s reputation pretty well. "The five speed is great if you are not running a lot of horsepower." Your typical 383 will have no less than 400 lb/ft average from 2000-6000 rpm. Then I just read about the aftermarket G-Force T5 using the stock case and pretty much nothing else. Good for 500+ lb torque in a 3300 lb vehicle. Impressive and light weight to boot. $1700 doesnt sound bad for price either. Nice!

Good advice since most are going to build an engine following the latest Hot Rod article or off the shelf parts without any experience or research. A 74 cc AFR will drop your 383 approx. 11.0 to a "safe" 10.25, which of course will work best with smaller cam. I'm amazed how many start with a cam and try to build an engine around it. Heads, flow, compression should pick the cam.The mag articles won't put you on the edge, but usually well into the safe zone. I didn't have the expertise, so I let a reputable experienced race engine builder handle the details with ocassional input. No race gas or timing changes for race day was one of my stipulations. You will be on the edge, but this will work was all I needed to hear. Its nice to see your engine builder regularly at the track on race day standing behind his product. John

Hardly run? A gross machine mismatch yes, but personal experience, leaky gasket no. No misses, idled fine except for eventually fouling the 2,4,6,8 bank with oil. In my case a poorly sealing manifold to head gasket right at the base of the valley. Just as somewhat worn valve seals or guides won't create a vacuum related miss, but still draw oil into the chamber. I've also heard of this when using silicone for a gasket seal which eventually is broken down by the fuel, causing the seal to fail.

AFR has a package for solid roller cams. Give their tech line a call with cam specs. They set me up with 7/16ths studs, valves, and the bigger 1.550 springs good for mid .600 lift. You also might want to visit Prestage.com and see how the dedicated drag racers are using small port heads and turning big numbers. As Dr_Hunt stated its more the combination of well matched parts. I dumped a set of larger port Pro 1s, 300+ cfm, for the AFR 195s, because for my 383 they didn't have the low speed velocity, didn't pull until 4000, and wanted more cam than I would personally like on the street. The Pro1s would have been great for 1/4 mile only duty. John

After seeing a good friend's WC T5 fail for the third time in his mostly stock TA with a wimpy 305, and a lecture from the local transmission repair shop where I was shown a pile of failed T5s many WC,... go for the T56. You always hear the T5 works...if you don't abuse it. Sweet shift the family car. Who doesn't want to abuse their hot rod? Its a royal PITA to change transmissions just because you banged a couple of gears. I opted for the aftermarket T56 with the .62 6th, lower torque rating than the .5 T56, but with the Zs light weight, no issues to date... I have a 383, 244 @ .050 cam, carbureted, 3.55 rear, 225 50 16 tires, I often cruise in 6th at 65mph, with no surging. Don't worry about redundant gearing with the torque of the V8 in a light chassis. Just because you can roll on and smoke the tires in the first two, sometimes three gears doesn't mean you should opt for a two speed. Heck I'd have fun with a 10 speed! Most of our local highway speed limits are 75 where the 6th is welcome on the highway. Yes it is more expensive, but as the saying goes.... John

Could also be a leaky manifold gasket pulling oil from the valley. One whole side of seals or guides usually doesn't fail all at once. Depending on manifold type and with carburetor removed, you can sometimes see if there is an oil trail from the manifold to head mating surface towards the valves. Also if heads or manifold have been machined without regard to eachother, angles don't match creating a problem like you describe. Just another thought. John

Local news paper this a.m. stated tickets are way up for noisy vehicles. Mine is really loud, so only a matter of time. Has anyone used the Dynatech Vortex insert cones? If so did they cut the volume appreciably? I can't spend $$ on a new muffler, so this might be a quick fix. John

No mine is an older demon. My cam is 244 @ .050. which according to BG was over the recommended size. I started playing with the idea of doing the job myself of resizing metering plates emulsion holes and air bleeds to Race Demon specs. My BG manual has all the specs so it would be interesting to see what happens. Perhaps they are more flexible in the newer design. They are nice carburetors and see them often managing the fuel in the engine shoot outs. Nothing wrong with pretty either John

My first Hybrid Z went together mechanically, during one football season. My wife is a big fan or I would have been served divorce papers! Supercharged 4.3 V6, No JTR or Hybrid Z site to rely on back then. I'm in the fortunate position of just enjoying the V8 car now for many years with zero maintenance other than gas and oil changes. Promise, it will be worth it. You'll be way ahead with a good body. Good luck and keep us posted. John

Forget the parts counter advice. Yes it can be done. I had an '85 5 pin module distributor and went to the four. Too many years, beers, monoxide headaches, and engines ago, but I remember finding the wiring diagram for the four pin and just using what was necessary. I liked the HEI for its simple effecient design. Get a good coil and aftermarket module, make sure bushings are all good, and the HEI is hard to beat. Compare your four wire and it should be pretty obvious what to use. John

I had a speed demon for a while. Pretty to look at, great construction, nice throttle response, but impossible to tune idle mixture. The Speed Demon is for camshafts up to 240 degrees @ .050. BG said they could recalibrate, for a fee and shipping. No thanks. Mighty & Race demons, are more suited to big cam duration. I ended up with an Ebay Holley 4150HP PRO 750. Comes with rear jet extensions, adjustable air bleeds. Useful if you are into squeezing out the last few hp, or have that funny rich spot on the top end due to your zero gap rings. Problem solved. You might check out the wise boys and girls at prestage.com. I posted a similar question a few years ago. Most will tell you you can't beat the classic holley 750 dbl pumpers, right out of the box. Plenty of big hp #s, (well over 450) and timeslips to back up their claim. John

Check Aerochamber off your quiet list as it is anything but sleepr! Compression ratio will play a big part of how loud your ride will be. I run 11:1, dual 2.5s into a flowmaster Y, 3" Aerochamber 14" offcenter in, center outlet. Honest, I've set off car alarms driving by. Shakes the house, rattles the windows, people three blocks away will be turning around, forget any conversation with your rider, the winged and stickered crowd pretend to tune their radio when you pull up at intersections. Different strokes...I prefer the "You don't want to mess with this" sound over sleeper. John

Enjoy the 4.3 for what it is unless you have substantial funds. Its compact, reasonably powered, and unique. Comp cams will give you great custom grinds for a reasonable price. Later stock iron heads can be retro fitted with larger 2.02 valves and have a bit more potential. Ebay is a good source for the later aluminum heads, but make sure you get corresponding manifold as some were raised runner or other than 23 degree. Brodix used to make some as well. You can make a great street motor with bolt ons, but still not on par with a very streetable v8. Yes the 350 pistons are a direct swap, valvetrain, oil pump, external bolt ons, but not the rods unless you have an aftermarket oddfire crank. Really now, a NA 500 hp 4.3 will need thousands and thousands of $$ in custom crank, heads, valve train, rods, and most likely a stouter bowtie block. I'd be willing to bet total cost is double than the v8. Racing gas stations are hard to find on road trips, octane boosters are only band aids. .600-700 lift cams? Already been stated its used for commuting. I was walking the main caps on my stock block with 16 psi Procharger blowing through wimpy stock heads. Changing out main bearings every couple of thusand miles isn't fun. Four bolting will help, but again for the price of being unique you're going to pay. If you are set on 4.3 (still one of my favorite engines) and need hp check out the SycloneTyphoon sites for advice. Dollar for dollar you can build a turbo screamer that truely can be driven. Procharger is another great choice, it fits, especially using the JTR mounts, reliable until you get greedy with the boost. Good idea to go with forged pistons at least. Again, what I'm saying is you already have the engine, some bolt ons will surely help, but don't be suckered into thinking it will be a cheap venture to get much over 300 NA hp. There used to be a Miata drag car, 4.3 aluminum 8000rpm ex indy(?) engine. Tons of nitrous, 8 seconds 600+ hp finally melted a piston. Our old Drag Hybridz drag race hero Ron Jones knew him. John

HybridZ has spawned another one. Quick, somebody give Wickedwild a shot of Nitrous, no, Nitromethane at 30 psi! Breath deeply, my son. Excessive hydrocarbons are necter of the Gods! ButlersZ, why the Scarab position if you want the best track handling Z? I though it was resolved that the JTR was best for balance in road racing, less weight on the nose and quicker response in the turns. Your "keep it sideways" sig and your wanting to blow away the usual street performance vermin makes me think you might be a power monger at heart. After all this is America, home of the stoplight wars,0-60, the 1/4 mile, and less than track smooth roadways. Remember, no one says you have to push the gas pedal to floor in an over powered car. Probably takes a better driver to know when and how much. I'm not swayed by an ITS champ. He probably dosn't give a hoot about a 10 second 1/4. Different road conditions/tracks favor different configurations. Where's your heart, at the track or on the street? The nice thing is a well designed Hybrid can really do both pretty well.

What's your cam duration? Your hp/tq peaks sound like a healthy bumpstick. Another factor to consider is your cruise rpm in 4th. Driving along at 80+mph, just to keep the engine from bucking isn't always a good idea. If your engine pulls ok from the 1800-2000 range, then the 3.55s should be fine. I'd guess the taller 3.36 gears would make using your 4th impossible at least at legal hiway speeds. I had a 700r4 and loved that short 1st gear! The WOT shifts were too hairy so I've since gone 6 speed. My 244@.050 duration is borderline at 75 in 6th. John

Wow, been away for quite a while. The never ending, evolving Monster HybridZ site! I have 11:1 forged pistons, 1/2 lines. Four port regulator. Currently run 140 mallory. I have old hot rod article that claimed it would support 650hp, but that sounds optimistic. I'm thinking of a 125-150 shot. Anyone use this pump, or better to upgrade? Also anyone try the Perimeter Injection plate from ZEX?

Ever have one of those mornings when you pass up the work vehicle and head staight for the Z? Mine was wagging its tailpipe as I entered the garage, so I figured, Friday, why not. Afternoon I ended up blasting through the hills behind Ft.Collins from Horsetooth reservoir to Masonville and back to Greeley. Lots of extreme grades and really sharp twisties and light traffic. Early on, two cycle guys tried to play catch up....sorry. My power to weight must have been better, not even in the straights! Those on a budget would appreciate the simple upgrades of ArizonaZcar springs, MSA swaybars front and rear, KYB struts, MSA f/r strutbars, Phantomgrip, Falkens, and Hawk brakepads with Ford HD truck fluid. Its nice to have unlimited Z budgets, but this works great for spirited canyon carving.Topping off the drive home, a few miles out of Greeley, a Honda with blowoff valve Phhhhht and engine revving pulls up alongside. The driver, cocky kid, points to my car and then over his shoulder. He drops a gear and punches it, BaHWaaaaaAAA. I pulled from sixth to to third and then fourth. A few seconds I heard the rev limiter stutter @7000 and 140 mph. Honda was a pea in the rearview.. and still had two gears. Its pathetic how much these guys pour into their cars with dogdish tachs, sewer pipe exhaust, fiberglass geegaws and pricey ineffective engine parts. I see his car at the local Rice shop. I hope he has the juevos to tell it like it happened. Yeah, I know there is always someone faster, but I'm still waiting. They're probably hiding in a garage under a cover. Upgrades are on hold as my concrete contracting is coming to an end in July. 27 years has ruined my wrists, now bone on bone. Bummer, got to figure out another way of paying the bills. In the meantime started a new garage addition for the Z Well, back in the garage for a week or so. Happy Hybriding! John

I really liked the aftermarket T56 ( from chevy dealers) now owned by Tremec. For ease of installation, T5 bell housing, clutch, throwout, slave. Centerforce makes a great dual friction glod. Chevy has really light nodular iron flywheels 15lb. New aftermarket slaves are of metal and much better than plastic. Ford truck master and line work great. Shifter comes out perfectly, B&M ripper for aftermarket T56 has super short throw. I did some beating around the slave area, but no big deal. Gear ratios are 2.97,1.94,1.35,1.00,.84,.62. No skip shift. Has electric reverse lock out, and provisions for mech speedo, also T5. Pricy, but worth every penny. Two thumbs up.