Howdy y;all so with winter coming I'm planning on gutting my T/A and start my resto mod process and when it comes to the engine, I'd want to do a 383 with 380+ hp and 400s for tq. I want to stay EFI. I saw a SP383 EFI for sale on chevy's crate engine website or could I stick with TPI and build off a base 383. or would it be easier to get a 350 TPI and build it from there? I don't know if this was already posted so if you could point me to a proper thread that would be great.
Sidenote: I want to keep my 700r4 and rebuild/beef it up.
SP383 EFI Turn-Key Crate Engine | Chevy Performance Parts (chevrolet.com)

 

Great questions! I’m listening it too.

 

GM crate motors are incredibly overpriced. I get the appeal that they come with mostly everything you need and often times, building from the block up costs the same (with LS), but you could build a solid 350 mill for way less than that, and use the remaining funds to support other needed mods like brakes, chassis, suspension.

 

GM crates are not cheap, no doubt about that. But they're great engines (you get what you pay for).

I got the SP/HT383 short block last year and put my existing AFR 180 heads on it and a relatively mild cam. I had the ZZ4 prior to that for >20 years with the same heads and a bit smaller cam.

But the torque output of the 383 is crazy, and that's with a short runner Miniram. Even with a cam/rocker combo at ~215° @.050, it has plenty of power everywhere up 5500 rpm (which is pretty much where I limit myself to). I wanted the smooth idle though, so this cam is glass smooth too as I put a 114 LSA on it.

In your case, if you're thinking about a stock TPI manifold use, you'll choke off that SP383 above ~4000 rpm. Though I'm sure it'll be mind-numbing torque at the bottom to mid-range.

 

The ONLY benefit that I see with a GM Crate is in regard to issues under Warranty (being that Dealerships are near most people).

Otherwise I feel they are too expensive and not worth the expense.

It's NOT like you are purchasing something "Made in America" anymore.