Mild 90 TBI build help

[Dentside_serria]

My 90 single cab short bed is finally where I want it to be cosmetically and it’s time to start giving the motor some attention.

I’m not trying to build a hot rod, if I were I’d carb swap and go nuts or 5.3 swap… just trying to not risk my life everytime I pull into traffic.

It’s a 1990 350 TBI

I’m going for a daily drivable 4x4 with a little extra juice then factory. I need to keep the TBI and can’t afford to go holy sniper.

I’m thinking mid length headers into 3inch single with high flow cat and flow master Super 10

Some vortec heads or somthing similar with a carb intake into a TBI adapter plate.

Some of my questions… does anyone have a link to some suitable heads that won’t break the bank.

Also what is a good tappet cam to run with a stock TBI system. I’m aware the TBI is the limiting factor but like I said, I’m not going for a high hp build, just as much as I can get out of it with the TBI. what are some cam specs to look for in a TBI cam

What is a link to a good cam you have run in TBI And what it required to make it run.

What is everything required for camming this motor as well as head swapping. Anything else I’m missing? How much HP should I expect out of a very mild build like this. I’m aware it won’t be a lot but I don’t want to do all this work If it only makes 240hp for example.


I’d love to hear what you guys have done for mild TBI builds, and everything it took, I’d love links to anything such as heads, cam, headers, etc…

Also I am running this through a getrag 5 speed.


Thanks!

 

[WICruiser-97]

If you are building a daily driver don't get too hung up on changes that are only effective at high rpms that you will probably never see in daily driving.

The stock heads get a lot of negatives associated with their restriction at high rpm that kills HP but they are fine for low end torque and engine speeds up to about 3,000 rpm. Vortec heads will help the high end HP but when you start talking about changing heads, intake, etc. you are getting into some serious money.

I'm sure others will be along with better recommendations but if you are really interested in a low dollar build I would refresh the original.

 

[Dentside_serria]

If you are building a daily driver don't get too hung up on changes that are only effective at high rpms that you will probably never see in daily driving.

The stock heads get a lot of negatives associated with their restriction at high rpm that kills HP but they are fine for low end torque and engine speeds up to about 3,000 rpm. Vortec heads will help the high end HP but when you start talking about changing heads, intake, etc. you are getting into some serious money.

I'm sure others will be along with better recommendations but if you are really interested in a low dollar build I would refresh the original.

Thanks for the input. Vortec heads should make more HP everywhere as well because they are higher compression correct? Combustion chamber is smaller?

 

[Dentside_serria]

If you are building a daily driver don't get too hung up on changes that are only effective at high rpms that you will probably never see in daily driving.

The stock heads get a lot of negatives associated with their restriction at high rpm that kills HP but they are fine for low end torque and engine speeds up to about 3,000 rpm. Vortec heads will help the high end HP but when you start talking about changing heads, intake, etc. you are getting into some serious money.

I'm sure others will be along with better recommendations but if you are really interested in a low dollar build I would refresh the original.

Honestly I drove my friends stock 97 and the vortec is so much faster than my 90 it’s not even funny. Id love to be at Least stock vortec power if not more, although I’m not sure it’s achievable on a stock TBI system.

 

[PlayingWithTBI]

Id love to be at Least stock vortec power if not more, although I’m not sure it’s achievable on a stock TBI system.

You can get up to ~275HP at ~4000 RPM with the stock 42mm Throttle Body. You'll need a fuel pump from a 96 Vortec (they're a direct replacement) and a little more fuel pressure (15+ PSI). You'll need an Adjustable Fuel Pressure Regulator and gauge. If you want 300+ HP and higher revs, you'll need to bore it out (46mm) or go to a TB from a 454 (50 mm).

Vortec heads with the Spread Bore intake and TBI adapter are sufficient but, your 1990 probably (more than likely) has the Flat Tappet "peanut" cam. The Vortec has a Roller Cam. Your block may be already set up for roller, you'll just need to get the necessary parts for it from the bone yard or maybe Summit Racing. I WOULD NOT BUILD ANYTHING WITH A FLAT TAPPET CAM!!!

Headers with a mandrel bent Y pipe to 3" exhaust and a high flow Cat, will give you adequate flow, a straight through muffler will give you more. The DynamicEFI EBL Flash-II ECM will make it easier to tune for efficiency and performance with a WBO2. It all depends on your budget. Have fun!

 

[L31MaxExpress]

TBI heads have the same size combustion chamber as a Vortec. TBI heads make more torque under 4,500 rpm than the Vortecs. A lot of the Vortecs added power was the sequential injection, the roller cam, better flowing exhaust and improved engine management.