I would greatly appreciate if someone can point me in the right direction.

It has been a while since my original post. Finally have some funds and engine crane to start the swap.

I have a 1977 350 and going to swap it out to TBI. I already have a computer, wire harness, standard TBI and 454 TBI too.

What I want to do is to install stock GMPP Vorec Heads (#12558060) and GMPP cam (#24502476) and basically make a GMPP 350HO. I would rather purchase the GMPP Vortec Intake for TBI instead of another carburetor for the same price. With carburetor the 350HO make 330hp and even more with Edelbrock RPM Air Gap Manifold and 750 cfm carburetor and headers.

From what I understand, the stock program in the chip will not work with vortec setup.


Thank you,

Waid

 

I bet it'll start up & run fairly decent, but tuning is the key to get most out of the whole system.
Tbi system like a cam w/ good vacuum for the map sensor. When you get it running, measure the manifold vacuum.
You'll probably have to have a way of adjusting your fuel pressure.

 

The camshaft that you have chosen will require tuning - there is no way of getting around it. I would strongly recommend EBL system from Dynamic EFI for this effort. Published spec for this GM cam are:
Duration at .050 in. Lift 212/ 222,
.435/.460 in. Lift,
112 deg LSA

Engine with this camshaft would probably idle at about 750 RPM at about 14 to 16 in-Hg of vacuum. Note that stock TBI (LO3-LO5) idles around 600 RPM and 18 in-Hg. With EBL taming lower idle vacuum will be much easier task than trying to go via chip route. As a comparison I have recently built and run 350 with CS1014R bump stick. This is a very TBI friendly cam (engine idles at 600 RPM), but it may not fill your performance requirements. Published specs
Duration at .050 204°/214°
.420/ .420 Lift
LSA 112°

The GM cam is not too far off, but my concern would idle tuning and you'll to alter VE, AE tables to get fuel correctly. SA tables is another story.

A carburetor intake can be used with TB adapter plate. Personally I do not like it as it may introduce potential for vacuum leaks, but it works. Contact DCtrumpet for one of the best TB to carb plates.

HTH

//RF

 

Waid,
I would stick to the smallblock TB (modded). That will be easier to get dialed in on the tune. It won't hurt HP capability. There is no reason a 350 has to run over 6800 rpm to make 350HP.

Adjustable regulator, good fuel pump, I think you've seen most of this info here before, sry so late to respond.

dctrumpet is Sean,...is SPR Performance...is,

http://www.tbiparts.com/

 

when i put a stock vortec longblock in my 91 i used a gmpp tbi vortec intake.i had a stock chip and tb.the only mods were an open air cleaner,pod spacer and catback.it started up fine but it kept giving me bad hesitation fits until i put an adjustable regulator on it turned the fuel pressure up to 13psi the it ran pretty good.my stock pressure was 9psi so the extra few psi made a world of difference.i would definitly suggest an adjustable regulator and bigger pump.

 

stock 305 or 350 vortec longblock?stock 305 or 350 chip and throttle body?