picking a comp cam for the 383

[55Willy]

I'm looking at either the 262X with .462/.480 lift or the 274X with .487/.490 lift model.

I'm running dart iron eagles, with roller rockers.

main use is towing,
remind you this is going in a 2 ton burb with 35's and 3.73's

 

[Mad-Dog]

The XE274H is the wrong cam for a 383 with 5.7" rods in a 2 ton tow truck,
that combination has a short rod ratio of 1.52:1 and is not comfy revving over 5500 rpm...........the 274 doesn't start making power until 1800 rpm.

you want a cam that compliments the high-torque, short-rev personality of long-stroke, short-rod motor, choose a cam that pulls clean right of idle to 5500 rpm........try to keep the LSA at or below 110 degrees and use 1.6:1 rockers to bump the lift.

I run a XE274H and it has a chop that my wife compares to a helicopter.....
she's a little pissed because the truck is too fast for her to drive now.

damn baby.........I'm sorry

 

[trailblazr81]

I have the 274 in my 383. With aluminum heads, RPM Air Gap intake, blah, blah, blah. Tho I dont really tow much. I would go for the smaller cam for a heavy tow vehicle. The thing is loud, choppy idle and has a gear drive. Definatelly hear it coming!! Right now it has 4.1 gears with 35" tires. Im thinking some 38's would be good. But first I have to fix a hard brake pedal and get the thing to stop throwing the power steering belt.

 

[Indyblazer]

Ask the Experts

When I built my 406 cube SB Chevy I had the very same question. I had spent BIG $$$ and wanted to get the best performance. I called the Tech Dept at Comp Cams. They are Terrific !! You need to have ALL the specifications about the engine AND the vehicle. Transmission gears, rear gears, vehicle weight, engine specs including carb/injection pistons, rods, valve sizes, cylinder head specs (valve & port sizes, Flow & CFM numbers etc)

Go with what they recommend!!!