Head help

[bamabaxter]

Trying to decide which heads to go with. I could use a little help. L98's or Vortec. Personally I think the Vortec's are the way to go but I can get a set of L98 for free. If anyone has any experience please let me know. They are going on a 350 w/mild cam, Edel intake manifold, Edel 600 carb, and a set of headers. Will i need more CFM?

[tbags]

The l98 is a good head esp. if it is free but the vortec flows better in my opnion. but you will need to buy a new manifold also

[Billla]

Vortecs significantly outflow the L98 heads and have a better chamber to boot.

If they're free and overhauled, that's a good deal and I'd take 'em for a mild build (< 1 HP/CID).

[bamabaxter]

I take it that vortec is the way to go. Best intake manifold for the money?

[Billla]

Unless you're planning to turn > 5000 RPM on a regular basis, the Performer or Performer EPS are the best choices.

Your name is pink because you haven't paid for your membership

[tbags]

Originally Posted by bamabaxter

I take it that vortec is the way to go. Best intake manifold for the money?

Edelbrock air gap is the best in my opinion - best flow best air temp charge

[Billla]

Originally Posted by tbags

Edelbrock air gap is the best in my opinion - best flow best air temp charge

Not available for Vortec heads - no flow difference as compared to the Performer.

IMHO, the air gap thing is marketing hype. I've seen NO back-to-back dyno results that show any benefit at all.

[bamabaxter]

I assume different headers are required also?

[bamabaxter]

Nevermind, I found out that the exhaust ports are the same as far as pattern for the headers is concerned. Thanks for all the help!

[piecesparts]

Originally Posted by bamabaxter

Trying to decide which heads to go with. I could use a little help. L98's or Vortec. Personally I think the Vortec's are the way to go but I can get a set of L98 for free. If anyone has any experience please let me know. They are going on a 350 w/mild cam, Edel intake manifold, Edel 600 carb, and a set of headers. Will i need more CFM?

The L-98 head is the exact same head design that GM used on their ZZ3 motors. There is ONE bad thing about the head's design, though. The HP peak is really low on this style of head. This makes the head a great boat motor head or a great street racer because of the RPM bands on them. The band peaks out at around 4200 RPM and then it is basically flat from there on up. I spent some time looking at different combinations when I was building my 1990 L-98 TPI motor up and I found that everyone had the same comments about the power curve of these heads. I did some looking at the Scoggin-Dickey catalog and read a few different articles and finally went with a set of vortec heads and a vortec base for my TPI intake. The combo will take my power curve on up to about 5800 RPM with the peak settling out a lot higher than the L-98 heads. I believe that if you use the vortec heads and include a well built set of 1.6 to 1 roller rockers with them, you have the ability to improve over the L-98 heads immensely, especially in the flow characteristics of the head design. I took my L-98 from a 240 HP motor to a 350 HP motor with the combo selection of heads, rocker arms, TPI tubes and upgraded injectors. Just my .02 worth.

[Billla]

I don't know how a head can have an "HP peak", but the FLOW on the L98 head levels out at a little over .400 lift @ 189 CFM (.500 to 199 CFM) - which is pretty poor. The stock Vortecs are making 216 CFM and 229 CFM respectively at those lift levels.

Note that using 1.6 rockers on a Vortec means buying upgraded versions - the stock Vortecs are lift-limited to .475, and a cam that would fit within that range with 1.6 rockers likely wouldn't have the duration or overlap you'd look for. I'd stick with the stock heads, the GMPP CHEAP self-aligning 1.5 stamped steel rockers and a cam of less than .475 lift and call it good.

[bamabaxter]

Thanks for all the info! I really appreciate everyone's help on this one. Vortec it is