TBI 350 or 383 build for 1994 Blazer

[PlayingWithTBI]

Stock cam and long tubes would probably put you in the HP ballpark and you won't have to get into pushrod geometry or cam timing at all.

IDK, that's a thought but, you're asking a 255HP L31 to put out ~50 -100 more ponies on TBI (instead of CPI) and LT headers alone? Maybe some tuning will get you close, who knows, it's worth a try.

 

[Sean Buick 76]

Up the compression and cubes if your willing to run premium fuel. If not then lower your expectations.

 

[Erik the Awful]

My goal is about 300-350 gross HP revving out to 5500ish

For this power level, don't spend the extra money on a 383.

No need for a 4-bolt main block. Nice, not at all essential.

But if you can score a 4-bolt block cheap, snag it now while you can find one. They're getting rarer now.

1. Yes to adding cubic inches with a 383 stroker kit. Have the block bored out, mains align honed, deck milled parallel to the main journals etc. also have the bottom skirt of the block machined or ground to clear the big ends of the rods. Have the deck milled to give zero deck to piston clearance then use a 40 thou gasket for optimal quench distance. Use the piston dish and head chamber size to get the compression ratio you want based on fuel octane you want to run.

2. Ditch the TBI style heads and use AFR enforcers with a regular 4 barrel intake. Use a sheet of 3/8” alum and make a simple adapter plate to adapt to a TBI. Use a 454 TBI and switch to a newer ECU and pay someone to tune it.

That's about $3000 on top of a decent 350 hp 35 build. That's a nice recipe for a 500 hp build. Except the TBI part. If you want 500 hp, ditch the TBI.

Don't have a lot of spare time but you want to do a custom engine swap hmm? You should be warned this is a hundreds of hours endeavor.

A 350 build and swap is fairly simple and easy, but the tuning is going to be the hard part. I ended up throwing a Holley Sniper on mine, which then ended up in a learning curve on why Holley products suck - too many necessary parts not included and too many crappy made-in-China parts.