Here are some bolt on ideas that I've been thinking about doing this winter. Would like your opinions & possible cam ideas.

All these items will bolt up to a 350 block as well, but right now I'm going to work with what is in the car until the bottom end need to be done.

Vortec 5700 heads. Casting #10239906 of from a 96 350. (ported & polished)

Custom ground cam at 0.510/.520 210/214@0.050 114 degree lobe seperation

GM Vortec TBI intake with a EGR block off plate.

Hi Flow 590cfm TBI unit from turbo city.

Headers with 1 3/4" primaries & 2 3/4" collectors.

Open element air cleaner.

And ofcourse some chip tuning.


I think that should get my lame LO3 pushing me around 250-300hp easy.

 

Not with the loss in compression you will have with those heads, unless u get the combustion chamber milled down.

 

What compression ration will that run at?

My current 305 runs at 9:3:1.

How much should I have those chambers milled?


The heads are being aquired from a friend. He doesn't need them so they are going to be a freebie.

 

Well, i believe those heads have 64cc combustion chambers while the stock heads have 58cc.
I think your compression ratio will drop to around 8.5/1 (or lower). SO unless u want to run a blower or get some domed pistons youll be losing power.
I would rather get some 305 TPI or 416 heads. Can be had for cheap, and that way if u get a 350 down the road, you can always use those vortecs for that engine.

 

If you're getting vortecs for free DO NOT PASS THEM UP. Those are great heads, what you gain in flow will well outweigh the drop in compression. Use a thinner head gasket and you'll gain some compression back then I'd think you'll be ok with it then use all the stuff on a 350 later on.

 

Im not suggesting he pass up on free heads, that would be rediculous. However, I think 416's or 081's would be a better choice for a 305, and that way he doesnt have to get a vortec tbi manifold, which arent cheap.

 

With any heads and cam upgraded motor you aren't going to want to run the stock intake anyways so why not let it be a vortec intake. The vortec heads way outflow any 305 tpi heads; vortecs are definitely the best choice in this case, especially if they're free. The only real appeal with tpi heads is that they can be had for cheap and port work brings them alive. Stock for stock vortecs will blow them out of the water.

You could get the Vortecs milled for probably less than the cost of TPI heads that you'd find, flat milling is cheap. I just wouldn't mill much off of them for later use on a 350. I think price is the only reason people go for TPI heads, they aren't some unbelievable stock head. Use the vortecs.

 

The GM Vortec TBI intake is $330.00.

Not sure if that intake itself will help in performance. But it will bolt up to the Vortec's & the TBI.

I have been looking around for ideas & searching this site. By doing this, I have read & come to understanding that if the Vortec's were milled 0.20 & use a .15" head gasket it should put me at a decent compression.


I do have a 350 block, but my 305 is still running strong. Why kill something that isn't dead yet.

This will also give me the option to build a 350 correctly by taking my time & buying the proper parts when I can afford it.

 

Sounds like a good plan of attack.

 

what about a 7516 or 7116 Air Gap/Perf rpm. They go for around $200 and flow nicely if you dont need EGR

 

Not a bad idea, but......


They won't bolt up to Vortec Heads or a TBI unit without modifications & adapters.

Why go through the headache of modiing a new intake & buying adapters when I can pay a little extra & get the proper intake?

 

actually both those numbers I gave are for the vortec compatible intakes. Edel makes a version for vortec heads. I highly suggest them.

 

Tell ya what.

Post some links to the page you found that info & I may consider it.

I looked up both those part numbers on edelbrock.com & no where did I read that stated Vortec or TBI.