I'm getting ready to order the vortec head kit from scoggin-dickey for my 1992 z28 with the 5.7 TPI. Will these heads be good to go or would I benefit more from them if I took them to a machine shop and had some work done on them? If I do take them to a machine shop, what would I need to get done? ported-polished? What do you think?

 

Depends what you want from them...are they the ones setup for the higher lift cam..i/e .500+? Should be able to run'em a is into the 12's.

You know you'll need a new intake as well? And none of this will be 50-state smog legal?

 

The kit comes with the intake and I don't have to worry about the smog issue. The heads come with the upgraded springs, so would getting them ported help them flow better?

 

Well sure, porting anything will make it flow better...question is, do you need it?

 

It is easy to f-up porting on vortecs on the intake side, I would make sure if you get them ported it is by a professional that has a flow bench and has dealt with vortecs before....the exhaust is a different issue, that responds very well usually to even amatuer porting.

 

I agree with ALLGO above. Unless you're going to step up to 2.02
valves, and use a very hi lift cam, don't bother touching the intake ports.
They're good for 400+ hp as is.

The exhaust ports are another matter, again they respond very nicely to no trick general porting technics.
If you want to invest in extra tweeking this is where to dump
some money in getting work done.

Pocket ported vortec flow test

This is very typical of what you can expect.

The gain on the exhaust side is not bad at all.
You can actual do this work your self. No rocket science
nessessary.