[screamingchief]

Originally Posted by goatman65

Springs are comp #995.130 closed,334open @ .550
Pioneer pshrods 5/16.I cant find the length.I had to get longer than stock because the lifter plunger was down in the body further than on the comp lifters that i was using with previous cam.
No stud girdle.Comp guide plates,7/16 studs.
Cam was not degreed.I'm suspecting this 'could be' a contributing factor.I run an E-brock geardrive with a 3 keyway crank gear.VERY hard to see the lightly stamped markings for +4,-4 or 0.There is a good chance i might have used the wrong keyway and installed it 'retarded' *4.
It does pull to 6000 and beyond with no problem,it just stops making power at 4900.
I'm replacing my 1-5/8 headers with 1-3/4.

I run 6x heads to keep a 'stock' look and i didn't have money at the time for alum.heads.I think to get low 11s/hi 10's the KRE heads would help a lot.

I thought your deal sounded familiar,so I went digging thru the archives last night after working on my race car,and yeah we talked about all this like last fall.

Absolutely power lurking in that exhaust IMO.

IIRC my suggestion was for headers with bigger primaries,I believe I suggested 1 7/8" with 3.5" collectors as what I would prefer to see on there,but agree going to the 1 3/4" x 3" headers is better than what you have.

I'm gonna be using 1 3/4" x 3" headers (hedman) on the 400 for my '70 Lemans/GTO race car with a very similar custon Crower solid cam (hell the back-up engine I'm building for that engine has a 290b6 ready for it),and even with what,50 some less cid I feel that size header is marginal @ best,the only saving grace to my situation is what exhaust there is will be 3" all the way back to the dumps in front of the rear axle.

And yeah,I'll bet $$$ that your cam is installed advanced,probably quite a bit.

And I'd put some stiffer pushrods in there,the pioneers are likely .065" wall,and I feel .080" wall chro-moly is the minimum,and the .118" wall pushrods are even better.

I'd also think long and hard about adding the stud girdle too.

Most combos like yours with solid cams like that peak right around or just over 5500 RPM.

Also,the chassis dyno sheet you posted showed it was a mustang dyno,and I have heard thru the grapevine that those can give hit or miss results for some,but somebody else like Harry K. would probably know a lot more about that than I do.

Oh yeah,the rwtrq was much healthier than the hp that was for sure,I think that was like 486 peak lb/ft @ the wheels,and something like 390 lb/ft average on the best run.

So that too makes me think the cam is installed advanced past what's recommended as well.

The KRE heads are always a worthy consideration when looking for more power than stock heads are typically gonna make,I'd get 'em thru SD if I were looking to buy,those guys do real good work.

Gotta go,finishing up my ignition panel installation/mock-up in the race car,and I'm burning daylight,then I shift to messing around in the garage working on misc. stuff for either my '72 firebird street car,or my brothers '68 S code 390/C-6 Ranchero GT.



Bret P.