which do you guys recommend for a tpi application to make better power sdpc vortech heads or aluminum l98 heads?

The vortec heads have a modified bolt pattern. The two inside bolts go in at a different angle than the outer bolts. If you use Vortec heads, you will need to modify your intake.

The L98 "Corvette" heads will bolt right up.

No, the Vortec heads will require a totally new intake. They don't have the 12 bolt intake, only 8 bolts. Very, very diffucicult to modify your stock TPI base for Vortec heads. Welding will be required.

Vortec heads picture


Given the choice, I would go with aluminum L98 heads. Given extra money I would buy a set of Trick Flow heads.

out of the box, vortecs flow alot better than aluminum L98's

I would reccommend good port job on the L98 if you are going to uset them. Once ported out, they can flow more than vortecs.

Vortecs are good heads and need the vortec TPI manifold. If you go this route, i would reccomend a port job on the exhaust ports of the vortec head. They dont flow good on exhaust side, so open that up to gain more power from the vortec head. If not, then gonna need a good split pattern cam like ZZ9 or similar.

For the budget, both heads are good, but make best power if you save up and get some trickflows, canfields, AFR's. trickflows can be had fairly cheap.

Orr89RocZ-your always on the job....good looking out

ok well l98 heads it is

To add to the subject of Vortec heads. the cost of the heads and special TPI base intake is almost the same as a set of Trick Flow 23° aluminum heads.

who sells the Trick Flow 23° aluminum heads for a good price and about what do they cost?

I'm thinking the Vette aluminum L98 heads have the old style bolting pattern, your 88 intake should have a different angle on the middle two bolts. I guess the intake can be filed out to work, not sure on this. Take a look before buying heads to be sure.

You just have to elongate the two bolts holes which were changed to 72*. Or, if you prefer, get a better flowing base. But the aluminum L98s can be made to flow extremely well.

These are the flow numbers TPIS get off their ported L98 heads:

BTW, none of these heads have any provision for an EGR. You'll need to fab something off one of the exhaust primaries ala Corvette.

summit racing sales them price starts at a thousand dollars.

1k huh..has any one just ported their stock iron heads?

A good port job will increase flow, but it's hard to get around the early chamber design. The newer heads have the heart shaped chamber that increases combustion efficiency, most tests show a worthwhile increase in power with just the Vortec head change.

sorry i needed to bring this back to life, but are you saying that the aluminum l98 113 casting heads do not have egr capability????? i thought it was a direct bolt on if you wanted to switch heads with a stock l98

The 113 heads don't have the EGR crossover passages in the center of the head, so they have to use an external style EGR setup that pulls vacuum from one of the intake manifold runners. Scoggin-Dickey sells an external EGR kit for about $60. This kit makes it possible to set up your EGR like the Corvettes. Another thing that makes it easier is to get either a Corvette tpi base intake, or use the Accel or Edelbrock aftermarket intake. These have the external style EGR port on the back, passenger side runner. The aftermarket bases have provisions for that and also the stock f-body style EGR. If you do a search, there's been a lot of threads on here about how to set it up. Kevin91Z put up a good thread about it quite some time ago. Personally, I'd just get the EGR function shut off in the prom. If you have to pass a visual check, you can always bolt up a "dummy" EGR valve that doesn't function anymore. I took a bad one and just filled it up with rtv, let it cure good, and bolted it on. Looks 100% functional at a glance. Actually now that I think about it, you woudln't even have to do that with the 113 heads since there's no passage to pull any vacuum at the valve anyways.

Also, the EGR does not function at idle. So, unless you are being tested on an IM240 dyno, they will never know if you make a "dummy" as suggested.

I've had the same dilemma, what heads for my 355 TPI build. I've done a lot of research on this. I've looked at iron vortecs, 113 casting L98 heads, and I've settled on the GM fast burn heads. Out of the box they are capable off 500hp with NO port work at all. GM only recommends that you polish the exhaust ports, and possibly the chambers, but no other work it needed......nothing......NADA. They can also use both perimiter bolt, or center bolt valve covers. They do need self aligning rockers though.

These heads do use the vortec style intake and for a TPI motor that's about $400 for a manifold from scoggings-dickey. They heads have a 62cc chamber and with a .03 overbore, a .04 thick gasket, and using a piston with -5cc valve reliefs that yields about 9.49/1 comp ratio. Well within acceptable range for the street.

For me I'd rather put my money into a head that has a lot of research and development in it, instead of spending $400 to $600 for a standard vortec/113 L98 head, and then adding $$$ for port work. Fast burns can be had from about $400 to $800.

I am chosing to buy a set of heads I can grow into as far as horsepower goes, and not out of. For me this just makes good sense as far as horsepower per dollar goes. In other words, more bang for my buck!