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305 Help


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Okay, I was building up a KA24DE Stroker, but recieved an offer I couldn't refuse and I realized I love the sound of a V8. Now down to the real stuff, I've done a lot of reading and I know the general concensus on the 305 is why bother when you can do the 350. Unfortunately since my father is paying for all the body work and that such has claimed a 350 is "too big" hence the 305 idea. Read all of this http://forums.hybridz.org/showthread.php?t=89381&highlight=305 and almost all of this http://www.lt1intake.com/files/faq.html . What i'm wanting to do is take a 305 TPI block

 

bored and stroked to a 335 ( http://shop.enginekits.com/osb/itemdetails.cfm?ID=341 )

shaft mounted rockers

crane cam beehive springs

crane cam (still up in the air on grind)

 

Now for the top end I want to do an LT1 setup. Meaning LT1 Heads, Intake manifold, etc. What my big question is will the LT1 fit on the 305 block? According the LT1 intake website it will fit on the 350, but doesn't say anything about the 305. I've heard that the blocks are the same and that the only difference is bore and stroke. Another question if I were to get a 350 LT1 Setup would I be able to de-stroke it? One more quick question can the T-56 6 Speed from a 1997 Camaro bolt up to the 305 block? My main goal is to pass smog, have a streetable car, that can hang with the occasional drag strip.

 

Thanks a ton, any help at all would be great.

 

Tyson

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If it were me, I would look into getting some vortec heads, maybe a comp cam XE268 or so. Then an Edelbrock performer rpm intake, 600 holley. Then some block hugger headers. I don't think I would bother stroking a 305. Just save your money for a future engine build, i.e. 350, 383, 406, or maybe even a turbo. Once your Dad sees that you can be responsible with the 305, maybe he will go for it. Anyway, good luck on whatever you decide.

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You could go even cheaper. Find a good used stock 350 ready to drop in with stock smog stuff intact if you have to pass those pathetic inspections. Better torque for street use too. Then save your money for something more later.

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An alternative is get a baby LT1. 4.3 liter I bet it would at least match the performance of a 305, and the setup would be the same as a real LT1. So once dad accepted that a larger engine would be nice you could simply swap in an LT1 and reprogram the ECM.

 

Good luck

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I have a 4.3L LT1 V8 long block. Yours if you want it. You could use the crank in a 350LT1 and that would give you your destroked V8.

The long block is yours if you like....just come by and grab it.....otherwise it is going to the scrap merchant.....

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A 4.3 Liter LT1!!!!!! I've never even heard of it, but sounds very very tempting. Anyone know any technical info on it? Googleing 4.3 LT1 pulls up very little outside of the fact that it was offered. So it should be able to bolt up the T-56 too right?

 

Tyson

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Google L99 rather than 4.3L LT1. Technically it isn't an LT1 but it uses the same EFI system. They were used in the Caprices, Roadmasters and Fleetwoods. I think they are rated right at 200HP which isn't to bad and as was stated earlier once you get it swapped and running it's a simple swap to the 350 LT1.

 

Tim,

If tfreer85 doesn't want that motor how much would you charge me for the crank and rods?

 

Wheelman

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Hey Wheelman if I go with the L99 I would be doing a complete rebuild anyways since I'd want to stroke it. Therefore I'd be willing to give you the crank and rods as long as you paid for shipping or would want to pickup. Thanks for the L99 code for finding it.

 

Tyson

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Tim' date='

If tfreer85 doesn't want that motor how much would you charge me for the crank and rods?

 

Wheelman[/quote']

 

I just want rid of it. I only bought it for the intake and valve covers. Looks like Tyson is gonna come by and snatch it up....

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Guest 73TPIZ
Thanks Tim any idea about the De-stroking theory? Also what about Multipoint FI since I'm looking into FI systems and wouldn't want to stick with the TPI system.

 

Tyson

 

 

Tyson,

 

not sure what you meant by this as TPI is multipoint FI. If your just want a different style FI then to each his own but my 305 TPI has served me well. I was running ~13.3s @ 100mph in the quarter with almost everything stock ( heads, intake, throttle body, injectors, torque converter). I had street BFG tires (245/60/14), a 2-5k Crane cam (shift @ 5200 and crossed the line @ 4800), and Corvette ram's horn cast iron manifolds and a stock R180 3.70 rearend. I turned ~2100 rpms @ 60mph with the 700R4 (.7 OD, 5-speed should be same) and got ~19mpg on a trip to Reynolds 2 years ago. Now with my mods I still get at least 19-20 mpg with more power and weaker motor. Due in part to the 3.27 ratio rear (~1800 rpms @ 60mph).

 

The previous posts are right though, I wouldn't go to the expense of stroking the 305 when you can go 350 much cheaper. Just not worth it. The 350 is a way better motor, IMO.

 

I used this motor as I already had it in a '86 Trans Am w/ decent miles or else i would have gone 350 at the start. I currently have a 0.30" over 350 (355) on the engine stand waiting to go together. But the little 305 just won't seem to give up.....

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Google L99 rather than 4.3L LT1. Technically it isn't an LT1 but it uses the same EFI system. They were used in the Caprices, Roadmasters and Fleetwoods.

 

 

Hmmm, this is a bit scary---how many "LT1's" are sold on ebay and from dismantlers that are actually not LT1's at all (5.7L motors anyway). :?

 

Not good. When I do an LT1, I will want an LT1 5.7L!!! Grrrr, something else to have to look out for now :neutral:

 

Davy

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DavyZ,

Just make sure it came from either an f-body (Camaro/Firebird) or a Corvette. The L99 was only used in the b-body cars (Caprice, Roadmaster and Fleetwood) and they have iron heads while the f-body and Corvette LT1 has aluminum. Some of the b-bodies had LT1s with iron heads (Caprice Classic/9C1, Impala SS, some Roadmasters and Fleetwoods), they are the ones that will be hard to distinguish from an L99. Easy way to avoid the problem is buy the whole donor car, that way you get all the electronics and lots of other stuff that comes in very handy during the swap.

 

Wheelman

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73TPIZ I was thinking something along the lines of this for an FI system if i went the non-LT1 way: http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=9249&prmenbr=361

 

Wheelman or Tim240Z, I've got a question for you or anyone else. Is the block the same as the 350? Crank and journal sizes? I figure the difference is in the stroke, rods, and bore size. Am I correct?? Also would I be able to use the T-56 tranny from an early 1997 Camaro?

 

Tyson

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The 4.3 uses the same fuel rail, intake, MAF, Throttle body, intake, opti spark, ECM, etc as an LT1. If set side by side they are identical. BUT

 

A 4.3 is EASY to identify. The L99's block casting number is "10168588". and "4.3" should be cast into the side of the block. The L99's heads have the number "10208890" cast into their sides. LT1 uses 24lb injectors and L99 uses 19 lb.

 

The L99 will have ~200 RWHP, but will have everything needed to upgrade to an LT1. The wiring harness is identical, and has MAF so all the work done transplanting it will be recovered. The ECM would simply be reflashed for an LT1 and cam etc you use. Do NOT modify the 4.3 look at it as a place holder for your future motor. It will do GREAT on gas and have some performance.

 

“265 = 3.750" x 3.00" ('94-'96 Gen.II, 4.3 liter V-8 "L99", 5.94" rod) “ From Click me

 

The LT-1 rod is 5.7", and the L99 is 5.94. The 4.3 has a smaller stroke than a 350 3.00" compared to 3.48.. So that said IF you go 4.3 KEEP the rotating assembly. I wouldn't even rebuild it I would install it, and put all my money to buy a real LT1. I know someone will say why not use 305 pistons and crank it MIGHT be possible if you swap the rods but WHY? A lot of money and bother to get MAYBE 20 hp, better to save the money for a real LT1 IMO.

 

The 4.3 has the same external dimensions and bolt patterns as an LT1, so it is a direct replacement for an LT1, and bolts to all the same transmissions.

 

Good luck

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