Heads from Penninsular

[scottm]

I emailed Penninsular last week but got no response, I'm hoping someone here knows.. They list 6.5 NA and 6.5 turbo heads. What is the difference, the pre cups? Are their heads GEP parts? Is it possible to buy GEP heads bare?

 

[Diesel Nut]

I believe it is the pre-cups and possible the angle of the heads.

 

[JayTheCPA]

I find that Penninsular is better with the Alexander Bell technology than the Al Gore technology; give them a call

 

[Missy Good Wench]

You can buy GEP HEADS directly from GEP as well.
Penninsular sells the good stuff.

There are two types of heads, the van an hummer type with the 60 degree bolt angle on the intake ports, and the pickup heads with the 90 degree bolt angle.

The NA and Turbo heads use different precups.

The Turbo heads usually have a diamond stamp on the cup and the NA has a square IIRC

They will all work, but the Turbo heads will make a tad more power with the larger ported cups

Emissions is also a factor.

 

[scottm]

Thanks Missy. Is GEPP related to GEP, or are they just a dealer? And does anyone sell bare heads?

http://generalenginepoweredproducts.com/

 

[WarWagon]

Adding to the above. From using NA precups with a Big ATT turbo: NA Precups smoke more with lots of fuel and big turbo's. You won't notice the difference with the (little) fuel the GMx can't handle before it hits 14 PSI. (Yes, slightly more smoke because the NA precup is at it's limit.)

NA is for MPG not power.

Again the difference is precups.

Going between 6.2 and 6.5 heads the injector angles also change. The 6.2 heads will work but be tight clearance for injectors, except the 1982 special thread injector and different rocker heads.

 

[Missy Good Wench]

Gep/gepp same same

 

[Burning oil]

I believe the difference will be hardend valve seat and larger precups for turbo heads (P400 style).
Im a distributor for GEP also if I can help let me know. I just sent a set of heads to Iceland of all places!!