Hi everyone.

I have a 1991 5.7 that I am needing to do some work on. It's got a lot of miles, but I think the low end is OK- I'm planning to do a leakdown test on each cylinder to gauge things first.

As long as that is OK, my plans are as follows:
Swap out the intake for a polished rebuilt replacement. While I am doing that, I will extrude hone the lower manifold. Since I am planning to rebuild the heads, I want to extrude home those, do a valve job and mate them up with a set of Dyno Don headers.

I know that there are all sorts of options; Stealth Ram, Super Ram, Dodge Ram, LA Rams, LS swap, twin turbo LS7. But I am just looking to get the old girl back to a peppy stock condition with a LITTLE improvement.

Given that a) I am staying with the stock intake and heads, b) I am in California so need to stay smog legal and c) I don't want some lumpy idle dragster- I want a smooth running driver that will get up and go when I stomp on it, I have a few questions:

1) will adding some Scorpion 1.6 rockers help, hurt?
2) since I will change out the timing chain, is a cam upgrade worth doing and if so, what one and how will it effect the driveability?
3) is a cam needed to make the rockers worthwhile?
4) what kind of horsepower improvement can I reasonably expect from what I have planned?
5) does any of this require a chip or reprogram- something that is WAY out of my league?

Any feedback is GREATLY appreciated!

 

I would put your money towards a aftermarket base instead of a extruded stock base.
A comp 268 cam would be a good choice. Yes you will need ecm tuning.

 

I found a comment by Dyno Don saying that cam won't work with stock heads...

 

Crane 2032 if your looking to stay under .470 lift.

 

Though extrude / honed is expensive, finding an aftermarket base is now also expensive... A few years ago a guy was dropping about 20 of them for $150 each new, now they go for upwards of $750 on ebay... they are getting harder to find...

If you're going all that route / expense / (extrude honed stock heads), with aftermarket cam and rockers, I would put the $$$ towards some aftermarket heads that will support the high lift...

 

https://m.ebay.com/itm/TPI-lower-man...YAAOSwrslabTDi

Here’s a extruded intake, you can get a aftermarket used base for the same pricing range.