1994 k1500 383 tbi

[Taz069]

Newbie here all. Having a custom 383 being built for my truck. But right now my main issue is in rebuilding the tbi pressure regulator. Yes it has been chipped. Upon disassembly of the regulator there was a spacer used under the diagram..... To increase/decrease pressure not sure. Seeing the regulator is unadjustable. Any thoughts? The spacer is far left old diaphragm middle new right. Should I put it back in?? Will discuss motor specs soon. Thank you

 

[Supercharged111]

Newbie here all. Having a custom 383 being built for my truck. But right now my main issue is in rebuilding the tbi pressure regulator. Yes it has been chipped.

So it's been "chipped" for the 350 and you're building a 383. If that's the case, your chip is unlikely to be anywhere near where it needs to be. Even if it was chipped for a 383 that's step 1, step 2 would be datalog and keep tweaking the tune until it's right.

RVMorse Marine used to make an aftermarket regulator but he kicked the bucket, I'm not sure what your options are now but aftermarket adjustable is what I'd want in your situation.

 

[Taz069]

The old motor was a 350 to start with. Dude wanted to race me on his new 2015 Ford f+150. 110 I passed him at 140 mph out of sight. Was just wandering if any had seen a spacer used in the pressure regulator area. Not sure if increase or decreased pressure. And your correct never checked on pressure. Have a dual 16 sitting waiting to go fan that is.

 

[Taz069]

The old 350 performed as a larger engine, as I explained to the engine builder. Pilcher Automotive "Billy" out of Enterprise. He build engines from around the country. This is my hands off it is his build. For what the truck is to be used for Here's a methanol he just finished

 

[tayto]

what injectors are you running? what is the estimated HP on the 383? that will determine what pressure you will run at.

 

[Taz069]

Tayto wish I knew. The pods are out now on the tbi unit. The motor to be around 425/425. 1,500-5,500 rpm. Quick motor break down. Fordged eagle crank internal balanced, 3.75 toss. 6.0 inch fordged I beams eagle. Fordged weisco tru street, rod pin in oil land for 8.5 comp. Block to be machined for stroker clearances, yes 4 bolt .010 early 70's block

 

[Taz069]

Tayto I can say this. I just replace the factory fuel pump in the tank with a new bosch complete sending unit, which is capable of up to 30-35 psi.

 

[Tim W]

For what it's worth I was going for the same build (ish). I was told all kinds of things (I needed this, I needed that ect).

I contacted Brian Harris at TBI chips and after sending him my engine build sheet, which had cam specs, he told me that it would be difficult to "burn" a chip that wouldn't be too lean even with the right fuel pump and Regulator.

I ended up going with a Holley sniper bc it has an internal Regulator. Just a thought

 

[Schurkey]

my main issue is in rebuilding the tbi pressure regulator... ...Upon disassembly of the regulator there was a spacer used under the diagram..... To increase/decrease pressure not sure. Seeing the regulator is unadjustable. Any thoughts? The spacer is far left old diaphragm middle new right. Should I put it back in??

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I don't see a "spacer". I see a "spring seat". The bottom of the spring seat sits on top of the adjuster screw. Of course it goes back in.

The regulator IS adjustable, IF (big IF) you can remove the weld/silver solder/melted-metal mess that GM installed to make it "tamper-proof".

There's instructions all over the Web for removing that stuff, and then turning the adjustment screw. "It's easy" they say.

So far, I've wrecked three regulators trying to accomplish that.

Here's one I broke the entire bottom out of. (And another of a totally-different design I haven't screwed-up...yet.)

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[CumminsFever]

My 1st gmt400 was an 89 that I had to put an engine into. I stupidly built my own motor, a 350 with 10.5:1 compression, edelbrock heads/cam/intake. I got an adapter that converted squarebore carb to tbi, then plopped a 454 throttle body onto it. It ran quite respectable for a redneck hack job!
Your tuner is correct, the 350 throttle body will be extremely difficult to tune. Perhaps you can adapt a 454 throttle body onto it and have them tune for that? If tuned correctly, it'll put a grin on your face that lasts for miles!