oldnrusty Posted January 10, 2007 Share Posted January 10, 2007 Hello Z owners. I have a good running 305 that came out of a one owner Chevy 1500 pick up. I do not have any drive pulleys , balancer , water pump etc...however I have complete access to a 1989 or 90 Astro van with a 4.3 v6. I have been told that the 4.3 is a v8 with the last 2 cylinders erased ( 8 & 7 ) . I have been told that all that parts that I need are a direct bolt on to the 305 v8 including the trans . The trans is a rebuild in the Astro . I will also use the ac compressor ( short unit ) . The 305 will be carburated. The trans is supposed to be a 700 4r . Have I been told correctly or is it a waste to tear down this astro van ? Is the JTR engine kit better than the Motorsport ? I am sure some of you guys & girls have answers for me .Please dont hold back the valuable knowledge needed for me to be on my way to a base v8 conversion. I have the mechanical knowledge and the tools to do this conversion so please be as in depth as you can.I also have a 5.0 Mustang ( rebuildable complete short block 1986 ) & a t-5 ( same car ) with flywheel & clutch assembly for sale ( Illinios based ). I do not have the harness but I do have the computer ( 5 spd with ac) Quote Link to comment Share on other sites More sharing options...
primadonna z Posted January 10, 2007 Share Posted January 10, 2007 Why not use the V6, sounds like you have everything. Probably makes more HP than the 305. Quote Link to comment Share on other sites More sharing options...
strotter Posted January 11, 2007 Share Posted January 11, 2007 Despite what you may have heard, 305's are perfectly good little V8's. A number of people here have done swaps using that motor, and I can tell you firsthand that a Z with a good running 5.0 gets up and moves. It won't be a record-setter, but it'll provide hours of fun with torque aplenty. It's true about the bracketry of the V6 fitting a V8. Though I have not used any brackets from a v6 on a v8, my neighbor has a pile of them in his back yard and they are visually identical to mine - the front-mounted aluminum castings type. There may be differences, but they are not obvious to the naked eye. I cannot vouch for the transmissions. I *do* know, however, that there are differences between the V6 and V8 T-5's, they are not interchangeable. I believe it has to do with the number of splines on the intake shaft. Quote Link to comment Share on other sites More sharing options...
oldnrusty Posted January 11, 2007 Author Share Posted January 11, 2007 The t-5 is from a Mustang gt. I took apart a 1986 Mustang gt & kept the engine & trans. I will use the Chevy Astro parts & the automatic from it (astro) . I have not found a Ford engine kit as easy to install in the 240z as the Jtr & Motorsports for the Chevy engine. I wish there was something out there to my liking since the little 5.0 ford motor in my eyes is todays 327 of yesteryear. As many know the 5.0 (Ford ) from 86 had horrible heads ( I trashed them ) . The short block & trans are for sale. These will provide $$$$ for the v8 swap also. Hey is anyone interested in a 73'000 mile 240z engine 1973 , a 1977 5 speed trans 280z attached to motor in car ( can hear run , still in car ). The 73 6 cyl has weber down drafts , crane ignition conversion xr700 , a motorsport header & I also have the 4 speed from the z that I took out when the car had 39'000 actual miles . Quote Link to comment Share on other sites More sharing options...
SSflyer Posted January 11, 2007 Share Posted January 11, 2007 I put a 305 into my S10 Blazer, and it surprised more than a few Mustangs. In a Zcar it would do just fine. I wonder what could be done to the 4.3 to gain some hp. Less weight, same power.... hmmmmm. Is there a supercharger available for a 4.3? Quote Link to comment Share on other sites More sharing options...
oldnrusty Posted January 11, 2007 Author Share Posted January 11, 2007 In a small light weight car like a 240 ...even with the 73 being heavier than the 71 I had ( a lot of the 71 parts are going on the 73) ...the 305 will be fine with a small hp cam & a edelbrock performer rpm air gap intake .I do have a 350 4 bolt main block awaiting a rebuild later. Quote Link to comment Share on other sites More sharing options...
defrag010 Posted January 12, 2007 Share Posted January 12, 2007 305's aren't as big of a turd as everyone will tell you. they always mention its small bore and what not, but the 5.3 gen3 motor has a smaller bore than a 305, and people are real quick to reccomend that motor. A good hopped up 305 with nice heads, intake/exhaust system, and a nice cam will make Nice power, and wont be that much short of a 350 in power levels with the same boltons. Quote Link to comment Share on other sites More sharing options...
primadonna z Posted January 12, 2007 Share Posted January 12, 2007 Why not use the V6, sounds like you have everything. Probably makes more HP than the 305. Just to clarify my earlier post. It was not my intent to denounce the 305 engine, but to draw attention to the strengths of the 4.3. I believe that that engine produced roughly 20 horsepower less than the 305. With the reduced weight of the V6, and the low weight of an early s30 it could be a real runner. If the man has everything for the V6 sounds to me like an interesting, economical swap. Can you imagine a Buick Grand National engine in an early Z. I am sure someone has done it, and I can imagine it was spectacular. Quote Link to comment Share on other sites More sharing options...
primadonna z Posted January 12, 2007 Share Posted January 12, 2007 Any feed back on how the car handled with that power arrangement? Quote Link to comment Share on other sites More sharing options...
Forces Posted January 12, 2007 Share Posted January 12, 2007 I can't tell you wether or not the 4.3 water pump, pullies, brackets etc. etc. will fit, however, junk yards these days are absolutly full of 80's camaros, firebirds, 1500 trucks. Tons of cars out there had 305's, and all prts you mentioned would be fairly cheap at a bone yard. That is ofcourse, if you find that the v6 isn't compatible....but a super charged 4.3L in a Z would be pretty damn cool. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted January 12, 2007 Share Posted January 12, 2007 I will vouch for the 305 too.. I have used 305's in both my RX7 swaps over the years, and trust me, a V8 in a light car is going to be quick no matter the displacement. Even bone stock and high milage, it hauled the old 85 around like you wouldn't believe! I think there was a problem with the cams in 87/88 (wore out really quick) but other than that, it's a good motor. If you're doing a 'base' V8 Z, I say a decent 305 will give you good bang for the buck. Now.. the later 4.3's ARE a decent motor, and I'm pretty sure the 'vortech' versions actually put out more than the earlier 305s did, but I don't think they came in the astros... Quote Link to comment Share on other sites More sharing options...
oldnrusty Posted January 12, 2007 Author Share Posted January 12, 2007 Many thanks guys. I will go ahead with the 305 swap . I love the sound of a v8 over a v6 anytime ( the 350z has the best sounding v6 that I have ever heard ) .The torque is another issue.If I wanted a 6 cylinder I would build the low mileage 6 that it came with ( 73 240z ). This car will be driven by not only me but my wife also. If it is brute horsepower that I want ...I can get it with my 68 400 Firebird . I have owned a 71,72,73 & a 77 as far as Z's go . The 71 being my favorite . I need a v8 Z to complete me . The 4.3 v6 sounds cool but I am not interested in spending as much on a v6 rebuild/supercharged motor as I would on a built v8 ...unless it was a Grand national turbo v6. The simplicity of a carburated v8 with hei /msd ignition , block hugger headers & a small cam is just what the doctor ordered for my illness. I will get some photos going soon. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted January 13, 2007 Share Posted January 13, 2007 Dan Juday has the nicest 305 powered Z car on this site! Davy Quote Link to comment Share on other sites More sharing options...
Forces Posted January 13, 2007 Share Posted January 13, 2007 You might also check to casting number on the block. In the mid 80's (86 I think) the stock cam was toned way down in a lot, if not all, 305s. This was due, so I heard, to the Corvette and Camaro being too similar in power range, so the Camaro/Firebird/TransAm 305's were under cam'd. I don't know if that affected the 1500 trucks though. Might be worth looking into, see if a new cam is in order. Quote Link to comment Share on other sites More sharing options...
Guest Gr8White Posted January 16, 2007 Share Posted January 16, 2007 Can you imagine a Buick Grand National engine in an early Z. I am sure someone has done it, and I can imagine it was spectacular. I believe there is someone on this site- I believe this is maybe "ScottieGNZ" (or something to that effect) that has a GN 3.8 motor in their S30.... Quote Link to comment Share on other sites More sharing options...
patzky1 Posted January 16, 2007 Share Posted January 16, 2007 My father still has his 305 silverado on the original engine at 250,000 miles. So, no cam problem with his. In fact, he's had the tranny rebuilt at least 2 times. It still lugs the truck around well, so yours should kick an S30 in the ass if it's fresh even though it's not a "350". Quote Link to comment Share on other sites More sharing options...
Ledphoot Posted January 16, 2007 Share Posted January 16, 2007 you know one of chevies baddest small blocks was 302 z28 motor. You can take a 305 and spin the PIZZ out of it! Crank is a large journal ( same as 350 actually interchange) small pistons mean less weight. Swap in a good forged piston, prep the rods with good bolts and polished beams have the whole bottom end balanced. Good headwork , Load it with nitrous or turbo or BOTH and zing it to the moon! Alot of the round track guys here are taking advantage of the # per cube rule and building 305 and 334 ( w 400 crank) and twisting them 9500 rpm! Some of these guys are even running "Claimer" parts ( cheap!) Quote Link to comment Share on other sites More sharing options...
TREVTEC Posted January 20, 2007 Share Posted January 20, 2007 hmmm, spending all that time to swap in a 100hp 5.0 sounds like a blast Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted January 20, 2007 Share Posted January 20, 2007 ledphoot quote; "you know one of chevies baddest small blocks was 302 z28 motor. You can take a 305 and spin the PIZZ out of it! Crank is a large journal ( same as 350 actually interchange) small pistons mean less weight. Swap in a good forged piston, prep the rods with good bolts and polished beams have the whole bottom end balanced. Good headwork , Load it with nitrous or turbo or BOTH and zing it to the moon! Alot of the round track guys here are taking advantage of the # per cube rule and building 305 and 334 ( w 400 crank) and twisting them 9500 rpm! Some of these guys are even running "Claimer" parts ( cheap!)" If you compare a 305 rod to a 350 rod side by side it'll be abundantly evident that they aren't as beefy and the beams are significantly narrower in both dimensions. I wouldn't advocate using 305rods even with good bolts IMO. Claimer "cast" pistons or hypers will grenade at piston speeds with an engine turning 9500 rpm using the 3.48 stroke 305 crank, let alone the 3.75 stroke 400, and the cam and heads required to reach 9500 far exceed budget and streetability. What class of circle track racing allows the use of turbos and Nitrous? Quote Link to comment Share on other sites More sharing options...
Ledphoot Posted January 20, 2007 Share Posted January 20, 2007 I forget that we have to be careful on exact specifics when writing in forum as compared to talking face to face. I also forget how literally some read what is written so let me broaded my comment..... 305 w/stock mildly modified internals will NOT do 9500 rpm and not with "claimer" parts either. I simply meant to reference the fact that circle track racers are using them and abusing them with good machine work as it shows what is POSSIBLE. I didn't say anyone used nitrous or turbos in circle track. I "ASSUMED" one would know the I meant drag racing and I apologize for seeming misleading.. With that corrected, you can build an adequate and reliable engine out of the 305. ledphoot quote; "you know one of chevies baddest small blocks was 302 z28 motor. You can take a 305 and spin the PIZZ out of it! Crank is a large journal ( same as 350 actually interchange) small pistons mean less weight. Swap in a good forged piston, prep the rods with good bolts and polished beams have the whole bottom end balanced. Good headwork , Load it with nitrous or turbo or BOTH and zing it to the moon! Alot of the round track guys here are taking advantage of the # per cube rule and building 305 and 334 ( w 400 crank) and twisting them 9500 rpm! Some of these guys are even running "Claimer" parts ( cheap!)" If you compare a 305 rod to a 350 rod side by side it'll be abundantly evident that they aren't as beefy and the beams are significantly narrower in both dimensions. I wouldn't advocate using 305rods even with good bolts IMO. Claimer "cast" pistons or hypers will grenade at piston speeds with an engine turning 9500 rpm using the 3.48 stroke 305 crank, let alone the 3.75 stroke 400, and the cam and heads required to reach 9500 far exceed budget and streetability. What class of circle track racing allows the use of turbos and Nitrous? Quote Link to comment Share on other sites More sharing options...
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