cam question

[bikedude189]

so here's my build:

258 crank and rods
677cp pistons +.030 dished to 23cc
deck block to 0
.043 head gasket
stock 258 or 4.0 HO cam
new lifters timing set, etc.
99+intake and bored tb
apn header with flowmaster 40 series
24# injectors

SCR 9.51 DCR 7.03 quench .043 4.59L


OR...

same as above with
26cc pisons and comp cam (popular one)

SCR 9.23 DCR 8.08

which one will have more torque? im at altitude, so could i still run 87-89 on the comp cam?
and is the cam from a 258 the same grind, etc as the renix one they give on the calculator? the 4.0HO cam the same?
and can i use the 96+ FPR on a 93 fuel system?
what kind of numbers do you think i'll see?


thanks all! i'm sure i'll have more questions for ya.

[aaronkeiser]

Seems like all these cams you've stated will work but it's a matter of what your rig is being built for. Are you building this motor street jeep or offroad jeep or both? I was under the impression that if you have a static compression of 9.2 or less it's cool to use the stock 4.0 cam but any higher and it will ping under heavy load. Also depending on what block you have will tell what cams you can use of cant use. Like the older style blocks cant run the newer style camshaft which was built for more low end grunt. Give some more details and we can see what's best for you.

[bikedude189]

93 block. 93 ho cam. dunno what vintage 258 cam. street jeep also for heavy offroad, mostly crawlin, as well as hauling stuff. it will be a dd for at least the first few years.
i think i'm leaning toward the comp cam, as it should give more low end torque, which is what i want. i rarely go over 65-70 on the highway, turning 1750 rpms...

you say 9.2 or higher will ping, but is that for 87 or 91 octane? and with a DCR of 7 i though you were supposed to be good, especially at higher elevations, as far as ping...