I have a set of Peanut port heads, that I can bolt onto a very nice 396. I have made a deal with my friend that wants it for his 69 Chevelle. He only wants it complete, and I told him that is the only heads I have. The only problem is, my 396 has the small domed forged pistons. I also would have to run a stock cast iron intake, as my Performer Rpm, I don't think will work. My compression with the open chamber "236" heads would be around 8.34 to 8.5 to 1. The block is decked. He wants to run a 280 Comp cam with the engine, which I think it may kill the engine some with that low of compression, valves, ports. He is going to run a 2500-3000 stall converter, and 3.31 gears. He doesn't have much money, and neither do I to find a set of closed chamber heads ready to go. He isn't looking for a street killer, obviously, he is just wanting something respectable. Anyone have any ideas how this thing may run. I would probably add a XE262 or a XE268 to this engine, instead of going so radical with a 280 Magnum. graemlins/beers.gif

A Comp 280 in that engine will be weak, especially at lower rpms. If he wants lope the 270 will be a little better torquewise and still have some lope.

i agree on your XE268 choice

he could always idle rich to make it rougher... or use alot of mechanical advance sooo his initial is down at like... 0btdc?????

At 8.35 to 8.5 /1 the motor will be gutless. Just not enough compression for a 396 motor. I doubt the motor will make anything over 300HP.

you make the call.......

396
7.7 to 1 comp.
stock open chambered oval port heads
272 crane cam
stock intake
600 holley
headers
stock convertor
th350
2.56 gears

strong enough for 14.40 in the 1/4 at 99 mph

this was my very first bbc all stock parts, cheap replacement pistons that was .055 or so down the hole. thick felpro head gasket. the only thing this had going for it was the cam and open headers.

same engine as above with close chambered heads 8.8 to 1 compression. ported the heads myself (first time ever) 284 crane cam,2500 stall,alum edy intake, POS 750 4011 something carb.

that was strong enough for 13.60's in a real bad tune up (carb problems) with 3.70 gears mph 105.


so you make the call......3700 lbs car.....

I had a low compression 396 orignally in my 67, while it was nothing like the high compression revver I built, it was a fine motor. Had the 820 heads and likely stock 10.25:1 small domes, so maybe 8.75:1? Unknown cam, but it ran fine. High 13's/low 14s with 3.31s estimated by Gtech. Felt OK.

Angle mill the peanut heads down and use a small Crane Energizer ( cheap!)and a Performer manifold. It'll be fine.

I thought the chamber on 246236 head was 113 not 119. that with a small dome say 100 thousanths,you'd get like 9.3:1.

The dome is a .182". The part number is L2240NF30 which is a Speed Pro forged piston.

I do not know anything about my current motor, but it does have the peanut port heads. It is FAR from gutless. Very strong runner, torque all the way through the gears, and never falls off. Never have run it at the track, but guessing mid to low 12's.
CHris

I have a .188 dome in my 408 motor.

.014 piston/deck, 104cc head, .041 gasket yield right around 9.5/1 ; 9.7 with the .022 shims.

Really need to verify the piston/deck ht and the actual CC of the heads.

I am not saying a 8.5/1 396 motor w/ peanut heads will be a total slouch, it will run decent enough, but when you get into the bigger inch motors, they really respond to increased compression. Everything about the motor changes. The engine pulls more vaccuum, the motor just makes more power across the power band.

I had stock 781 heads on there with stock head gaskets, and a Comp cam 294s in it, and it had major torque. I didn't know the compression would be so low when I built it, but it ran good. It just didn't pull much past 5500 rpm. I figured even with low compression, I may be able to pull some more torque out of this with peanut port heads with a much smaller cam,(260-270 duration) probably without sacrificing much top end. Am I correct on this? I have the Performer Rpm, this isn't going to be able to bolt on the Peanut port heads will it? The ports on the intake would be significantly larger. Don't know if it would bolt up. Anyone know? :confused: Would the compression be much higher if I added very thin, steel shim, head gaskets?

Dumb question guys, but when referring to the " peanut port " heads, are you referring to a 68-69 oval port casting, like I would have on my '69 396? Or are you referring to some of the truck heads I've heard you guys talk about?

Originally posted by 4spdrat:
Dumb question guys, but when referring to the " peanut port " heads, are you referring to a 68-69 oval port casting, like I would have on my '69 396? Or are you referring to some of the truck heads I've heard you guys talk about? The mid 70's truck heads is what I have.