Cam Size

[Cuda Kid]

This question is for a buddy of mine that's rebuilding his engine. The car is a 73 Cuda, 340 w/ 727 auto. J heads, engine going to be bored .40 over most likely, this car is going to be used mainly for street driving, but he wants it to have alot of power. He wants to get the camshaft with his rebuild kit and he's looking at the purpleshafts, but he doesnt know which one to get. Some help on this from the guys that drive 340's on the street would be great.

[Marc]

Are the heads 1.88 or 2.02?
What rear end gears?
What compression ratio?
Any way to get more info??

[Cuda Kid]

Rear end is an 8 3/4 with 3:55 sure grip, The compression ratio I'm unsure of because he bought the car with the motor disassembled but it was an all stock 340, the guy he bought it from gave him performance J heads. If there's anything else you may need, let me know and I'll try to get it for you.

[Darn Dart]

If the car will see alot of street use I'd go with the 268/272 - 450/455 lift purple shaft. My brother-in-law runs the 280 - 474 purple shaft in his 73 360 powered Duster and it needs at least 3000 true stall to work well. He first ran it with a 11" 2400 stall and it was a dog out of the hole. The new Comp Xtreme 268 cam would work great with the 340.

[PRO]

The real factor is compression ratio when selecting a cam,Id find out what itll be for sure instead of gambling on a combo that may not run well.Theres enough people on this site that could tell approximately what itll be if you give us certain info,head gasket thickness,piston heigth,that is how far below or above the deck the piston is at tdc,or piston part#, we already know you have J heads,with this we can relatively close in estimating.Heres a decent rule of thumb,8.5:1 use P4452759 its /430/450,9:1 use P4452761 its the 450/455,9.5:1 auto use P4452992 its the .474/.474,w/4 spd use P4120231 its .484/.484,with 10:1 use P4120233 its the .508/508 but youd better have aluminum heads to run 10:1 on pump gas.Have fun,go fast ,dont look back,............PRO.......