Hey guys, first off this is a fun project for me and my old man to do, I want to do something different, challenging and fun. What could be more different, challenging and fun than kicking *** on a 305 block with a pair of snails? I'm looking for advice on sizing these turbos, preparing the tpi setup, heads, pistons,cam etc. I'm hoping to attain 6-700 dd hp hopefully more with the boost turned up for the strip. The car Will be t56 swapped rear end is still undecided. All piping will be built from scratch by me. I just want good reliable power. Car will be Sunday cruiser so it can be a bit on the radical side of drivability.

I shouldn't have to say this but I will. I'm well aware of the advantages and hp difference of starting with a 350/383 or ls swapping. I get it I really do. I've even told people to junk their 305's. But I wanna have some fun with this so bear with me and help a brother out.

 

I wouldn't bother with building a stroker if you're going to boost it anyways. Keep it a 305....but...you'll need forged internals unless your tuning skills are spot-on. Maybe do a bunch of research on how to tune a TPI system for boost...but - if the 305 should blow, then you can find another 305 about anywhere cheap. But I just can't see a twin turbo 305 being a reliable DD...and 6-700 HP goal sounds a bit lofty to me without some major boost.....

I won't mention since you're aware that going with a 350 will gain you more power with the same amount of boost, especially since you can bolt on heads that actually breathe onto a 350....

 

Yeah the forged internals are a given. I'm having a hard time finding a forged kit. I'm wondering if I'll need to have something made custom. As for the 334, I figured since ill be rebuilding the engine from the ground up it can't hurt to stroke it. I looked around for heads and there's a few options but to be honest when it comes to picking heads for a turbo build I'm completely lost same with cam. Especially for an odd ball build such as a 305. For my truck with the vortec 350 it's a quick Google search away pretty much every combo has been tried and documented same with my C5 Vette. I can look at dyno sheets for just about any combo I could think up. The 305 is uncharted territory. Which is mostly why I'm intrigued by it. I've even been considering selling the C5 to help fund this build.

 

Crank is easy to find. Rods easy
Pistons not so much but some do exist

I wouldnt mind trying stock crank with a good set of rods and pistons. It probably will live

I am more concerned with stock 2 bolt main block. I would lean towards splayed 4 bolt cap conversion on the center 3. Maybe look at pro gram engineering for caps. Mahine work is gonna be pricey tho. 400-ish to align hone the mains to fit caps but you want that strength

For twins i would look at maybe some small 60 mm units. Small ar t4 or larger ar t3. Would spool quick enough. Probably t3 be best.
Turbonetics 60-1 with 57 or 62 mm turbines
That be some good stuff

Or a single t76 would likely do it. Cheap vs racing 7875 would be awesome