I figure I'll post this here since it's not about a 231 or even a Buick engine, but I'm trying to get some thoughts on it from ask those in the know. =) Back in the day (early-mid 90s) they made a 4.3L version of the LT1, it used a 3.0 stroke and a 3.874 bore. The block is the same height as the regular LT1, the piston pin height is the same as well, to make up for the crank's shorter throw the rods are 240 thousandths longer to compensate. I've calculated out the drop with stocker pistons and regular 5.7 inch LT1 rods at about 6:1 give or take a bit. While I would like to get considerable power from such a motor, it's going to be more of an experimental setup to just play around with. Well, any thoughts?
4.3l V8
- Thread starter Drac0nic
- Start date
current plans involve an AWD astro van as to make it closer to a Syclone in steetability. There's a lot of rice here, gotta do battle and show em some muscle 
if I can I may just try to haggle my friend out of an old suck through 3.8L he's got from a "before black" car. I just like the idea of walking the path that most don't travel.
if I can I may just try to haggle my friend out of an old suck through 3.8L he's got from a "before black" car. I just like the idea of walking the path that most don't travel.far as it goes I'm thinking a set of 305 pistons would work out all right, the pin height is the same however the bore on a 305 is ten thousandths bigger so I don't think it'd be an issue personally. Quite honestly what I'd be afraid of is how the rotating assembly would balance, but there should be plenty of meat in the crank to lighten it with the shorter and probably lighter rods. A standard 4.3L V8 set of heads has 38 CC head chambers on it, so a piston designed for 9:1 CR and 58 CC heads would work out I think. The 302 is a tempting idea, but if I did that it'd definitely be going in a G body or a 280ZX (easy swap kits avalible, light as hell) or something like that, I'd be scared of not being able to push an astro van off the line easily with it because they're heavy, probably 1500 pounds by the time you get done versus a Z-car. Yeah, I know the 700R4 would probably be an issue as well, but the SyTy case is the exact same one used on the Astro van and the trans can be built up. Sure as hell won't be the easiest way of doing it, but it should be a wild time when it's done.
drop a 350 in it? I'm half ways tempted to throw a 231 turbo Buick motor in it honestly, I don't think I can get an AWD BOP pattern 700R4 though (if anyone can prove me wrong on this I'd be greatful) I hate to sound like I'm grumbling about it, but the 350's dead man. There are actually quite a few of the 350 vans floating around, I want something to toy around with instead of the monthly buildup from Chevy High Power or something like that.
I could very well be wrong but when I was into LT1 cars I remember this motor and isn't it exactly the same size externally as the 350 LT1? I remember they made a smaller LT1 that was put into Caprices and I think that's what you are talking about. If it is, then you may as well put in the 'real deal' LT1. Same size, 2x the power! (well not 2x but much more and more aftermarket parts available) I had my 95TAm6 running 8.10 with just a handfull of bolt-on's in the 1/8's. Junk tires, gotta love the LT1's.
