New here. Lurked, searched, and starting to explore further.

I have seen conflicting posts about the feasibility of porting a stock TPI base for using Vortecs. I want to upgrade to a different head than my '87 F code 305 has, but the price on Vortec bases kills the advantage of a cheap set of Vortec heads. I ain't lookin' for killer hp, and I ain't lookin' to race. But I'd rather port the stock base than have to port a set of heads.

Anybody else thinking the same thing?

 

...I have....
The biggest issue is the bolt pattern difference. I have done a few now by drilling and tapping the heads to the pre-vortec bolt pattern. You have to run more than just stock intake gaskets to do this. I have run double gaskets as well as the thick gaskets, both work well. I set the gaskets and intake on, slide a distributor in, and line up the ports. Make sure the dist turns easily, meaning the intake is sitting properly. Then center punch the holes into the head surface. Pull the intake, heads, etc and drill and tap. I reccomend setting the heads on with head gaskets and tightening 4 bolts each to insure
everything is sitting properly.
- By running the thick/double gasket(s) the intake sits higher, which aligns the ports more evenly. With just a small amount of intake port work, everything works out very well. - You'll have to put bolts/plugs/something in the vortec holes (I used bolts and washers after intake install) to plug the factory vortec holes off because they go through to the cam valley.

this is the best way I have seen to do it. It's about the only way that properly aligns the ports...

later, justin.....

 

 

The bolt pattern on your intake manifold is a 12 bolt and vortec heads are 8 bolt. Even though other intakes arent cheap you will be a lot better off getting an aftermarket one since the factory one is a big bottle neck. I went with vortec heads on mine and the mods listed. Im happy with how it turned out.
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Mods. GMPP Vortec heads, Comp Cams XR269HR, Crane Gold Rockers, Hooker headers, SDPC intake manifold, free flow exhaust, Air Foil, TB Bypass, K&N filter. Future mods, TPIS Runners, AFPR.

 

The Vortec intake bolt pattern is completely different than the pre-vortec stuff. NONE of the bolts line up.
- No you don't have to have the valves or anything out, all you're doing is driling and tapping the intake surface. You have to center punch the intake surface on the heads for the pre-vortec intake bolt holes.

 

Sorry to hijack this thread, but do you have any track times with your setup? I am curious about the cam.

Oh and I second the opinion of getting the correct intake.

 

I dont have any track times yet. I just got it all together this winter and have only had it on the road a few times. As soon as the drag strip opens up again ill take it down and see. Havent had a chance to top it out either but I would like to hit 150. Soon as I get my track times Ill post them.

THANKS

 

 

deffinition of "boat" - hole in the water in which one throws MASSIVE amounts of money.....

I've gotten away from them....for now....
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also, the vortec intake isn't enough better flow than the stocker to justify it simply for that reason. I can port a stock base and get about the same numbers as the ported vortec. - close enough for the girls i date....
- anyhow, i can't justify spending money on anything I can build/do myself. That's how I have been able to afford what I do have.

 

 

You .510 of lift might be a little more than you need.

 

I'd say it your combo/idea sounds pretty good. The cam might be slightly big, but I've seen slightly large cams do much better than most people seem to think(I'm running 11's).
- Should make for a great street set-up.

 

I'm going with the Vortec heads/base, junk yard heads, probably going to have to go new with the base, unless I find something soon. I've been looking at what cam to get now and called comp cams. They recommended either the XR269HR (.495/.503 218/224 112LSA) or the XR264HR (.488/.495 212/218 112LSA). By what I've read so far the XR269HR sounds like it will work well for me.

Stingray69, where in MI are you?? Maybe we could help eachother out.

 

 

Cool, thanks for the info . The heads I was referring to were Vortec heads, so I think that the exhaust would need a little help. Unfortunatly they need a lot more machine work than I thought they would, they were NOT off a running motor So much for vorteccs being the cheap alternative, I'm going to see if another shop will give me a better price, or if I can get my money back.