different cam and rearend ratio

[tractorsx]

I have a 66 c10 shortbox, with a 2 bolt main 400 engine out of a 1971 impala, with a auto tranny in it. Motor is out for a little fresh up nothing special, right now I don't know what cam it has, but if I was going to change it what should I put it it? Next question, it is running 3.73 gears changing to limited slip so I can make honest double stripes!! Should I keep 3.73 or go to 4:11?

[Rich 5150 69]

There`s alot more than just swapping a cam, whats your compression, heads, valve size, induction, hedders, which trans, has the block been zero decked, bored. we`ll need a little more info to be able to make an informed suggestion.

[Captainfab]

I agree.

Originally Posted by Rich 5150 69

There`s alot more than just swapping a cam, whats your compression, heads, valve size, induction, hedders, which trans, has the block been zero decked, bored. we`ll need a little more info to be able to make an informed suggestion.

As for the rear gears. With the torque that the SB400 makes, depending on what tires you will be running, I might step up to a higher gear instead of lower gears. Also depends on useage of the truck. Here again, we need more info.

[cortcomp]

I always caution this when speccing out a cam/motor/drivetrain: be HONEST on how you drive. don't build a bigger motor that wants to be at 3000/3500 rpms all the time, its not as fun. I build a beast of a 462 in my pontiac, it has torque all the time but it really wakes up at 2700ish. Cruising rpm at 75MPH? 2200. I mean it works well because it's stick and it has 500 fr lbs of torque like all the time, so it doesn't "lug", but i rarely get into the fun RPMS because i just don't drive like that. I should have either went with 3.73 instead of 3.42s to get those rpms up some, or specced a less lumpy more friendly cam. But i just couldn't give up the numbers that cam was giving me FWIW

[bama63]

power brakes (if equipped) and torque converter need to be considered when making your cam selection also.