[erikgto]

Thanks for the great info so far!

Since I have no access to other heads, how about milling the 6X-8's I have to get into the right compression ratio, around 8,5-1.
How much on the head and how much on the intake?
Will I run into trouble with my stock replacement pushrods?


.

[95ramairformula]

Erick
The 6X8 heads have huge chambers around 98cc-103cc. IMO they would not be worth
the trouble to cut. I wouldn't cut them more than .060 which would not really help in the compression increase anyways. .060 = 12cc Cutting them .060 would get you into the low 8 range in compression. Not enough. Yes you would also have to mill the intake side of the head the same amount. Yes pushrod geometry would have to be checked.

6X4 would be a better choice. Better yet would be a 62 or 13 head which generally cc out at 75 to 80 cc.

I know you already have the 2801 cam. But if it were me I would wait until I could purchase the XE 256 and do it right the first time. With low compression motor like you have with the compression probably in the mid to upper 7's the Compcam would be my #1 choice. Go with earlier heads in the 75cc range the 2801 would work very nice.

[PONTIAC LARRY]

Originally Posted by erikgto

I just want to have a spicy cruiser, not a race car. So I want as much low end torque I can get. I'm not interested in high rpm horsepower.
erik

Get a new 4.25" stroke rotating assy = 461 cubes with a .030 over bore.. Then your 6x-8's are perfect at 9:1 or so without milling , use the 2801 cam and egr qjet manifold. Superior torque from idle to 3000 rpm. Had a buddy with a 74 Ventura , th350 , stock converter with 2.73 gears. It had stock 6x-8's on a 455 block (9:1) summit 2801, qjet iron intake and 3 tube headers. It ran a best of 13.2.... stroker kits arent necessarily race parts, just torque parts

[95ramairformula]

Originally Posted by PONTIAC LARRY

I said 8-9.5:1 , my mid-low 2nd 70-1/2 T/A was a undecked 70' 400 block with cast 8 valve relief replacement pistons. Regular Felpro blue gaskets and #12 big valve heads( my compression was no more than 9:5, probably less. stock 70 intake and 750 Qjet, th350 , with 2800 11" , repop HO/RA manifolds ,2-1/4 pipes, 3.55 gears. I did not say his exact combo would run 13's , merely what I have done with that cam in a comparable combo. Another buddy at the same time, had a 78 t/a , 400, with 2801 summit cam, small valve #15 68 heads, headers, iron intake, qjet , 3.23's , th350/11"... we were dead even at all speeds , every time we raced. Another one.. 80 Formula ,SUMMIT 2801, 400 , 8-valve relief cast pistons, 3.23's , th350/stock converter, log manifolds, #62 heads with matching 69 Qjet intake.. it went 13.7@102 on street tires in the 80's., Another one.. 76 t/a 400 8-valve relief pistons. low-compression..summit 2801, #11 heads , small valves.. 8.0-8.5:1, th350/stock converter, log manifolds, 2.56 gears, no track time , but it ran very well. Had some hwy races with motorcycles and 454 1/2 swb pick ups.. did well against them..Probably ran 14's...
I am not calling any better than 14's for low compression combo, but with a sharp tune ,.. it can be ok... Lots of Comp Cam cheerleaders out there, but I and my friends are not.. Summit Cams have a great bang for the buck and also Doug Herbert is cool too..
Lots of cars are dogs , if the owners are not experienced or knowledgeable tuners or drivers for that matter.. Thats normal.. and man .. ditch that Torker II !!!
All I can say is a 2801 in a 400 works great and has predictable results and economy/idle quality better than a 110 ls Comp.. 112ls ..remember street car.. my car ran a best of 13.3 ..it turned slower times on other trips too..13.5,13.7..just mentioned the better ones.
This guy should try to find some cheap 68 small valve #17's or at least some 6x-4's or 73-74 #46's ..raise it up from 7.6:1 to 8.1-9:0 depending on which heads.

I must say some strong running motors. Not at all suprised with the compression they are at. Bottom line is the Summit cams are a good bang for the buck. When it comes to low compression ( under 8.5) the smaller XE cams from Comp flat out perform the Summit cams. The engineers have done there homework well on these. I have also heard that the new smaller Lunati Voodoo cams are also very good also. I really like the Crower cams and have had good success with them.

I have a friend with a 455 in a 65 GTO 4spd car. It has E heads and a Comp XE 274, it will flat slam you in the seat. Its what I call scary fast.

[PONTIAC LARRY]

I agree a very small 110ls cam like a 256xe is a very good choice for the really low compression 7.6:1 motors.. But I doubt anyone has gone thru the trouble to do a heads up test against the smaller Summit cams on the same test car..This a guy already has the 2801 , his problems was the torker II and holley combo.. Just going back the stock intake/carb stuff would help him alot. Maybe he might put better heads later to kickup the compression..

Now my experience with the larger Summit 2802 in a 10.5:1 455 (same 80 Formula mentioned above ) 3.23's and the shortblock I built 14 years earlier turned a best of 12.1@110 on motor , had turned low 11's on a 125hp powershot not using it off the line..

I ran some 13.3's@104 today in my heavy 3900#RW 68 GTO , it has the original 400 motor/400trans, and 2.93 Safetrack..12" ported #16 heads,2500 stall, Ultradyne 278/290 SR on 225/70R14 street tires / Rally II's.. going thru the traps in 2nd gear at 6000rpm..iron qjet intake and iron HO exhaust..made it the semi-finals today in Super Muscle, Texas Muscle Car Club Challenge Series..

[95ramairformula]

I agree with the factory intake and Qjet would really help him out.

13.3's thats pretty impressive and with 2.93 gears. Gotta love that Pontiac torque.
Those ported heads are definetly showing up with the mph. Sounds like a great day.