I was wondering if any of you have had experience with this camshaft, Comp Cams part number 12-250-3. Do you think it will work, or is it too big for a 10.25:1 385 stroker. I'll be using a 4L60 (700R4) with a stall around 2,800 rpm's and a rear gear somewhere between 3.73-3.90:1 and approx. a 26-27 inch tall tire.

Any thoughts or suggestions?

I do not have experience with this cam but I have a 381 (I think... .020 over) and the XE274 cam, 700R4 w/ 2400 stall and 3.36 gears (soon to be 3.55). If I had to do it all over again, I would go one step smaller to the XE268 or a custom roller cam. I have about 11" vac at idle and am running a q-jet which I have not sorted out yet. I have seen dyno tests with my combo and with the 268 and the 268 produced more power under the curve with better idle. If you really want that cam, go with a little more stall and at least 3.90s. Thing is, this should be a torque motor and that cam will want RPM.

It is kinda dependant on what you want out of it. It not terrible Id say, it will work well with a 3.90 gear(4.10 if you had the option but 3.90 will work) and the compression is good. The converter is marginal, but it will work as well. Id say a 3200-3500 would be good also if you had the option. The big thing will be your cylinder heads. Thats definitely a 6000+rpm camshaft so you will want a good head that can feed the larger displacement small block at high rpm. Dont expect lots of low end or street manners, but it wont be terrible either. Id say that that camshaft has 420+ horsepower potential with the rest of the top end being good enough to keep up with it. Also, it oughta run mid 12's at least as long as the drivetrain would keep up to it. With a descent cylinder head and your compression and converter being as is, Id still bet on a 12.80. Now if you dont feel like your heads are completely up to running strong over 6000rpm, nor do you have any plans whatsoever to change the gears or converter, something a little more mild(closer to the XE 274) might be a good idea so that you dont have a cam thats outrunning the rest of the engine and drivetrain.

To give you a point of reference:

I'm running the XE284 in my 383.

AFR195 heads, 10.75 compression, Edelbrock RPM manifold, Holley 800DP, 1-5/8 headers...

I put down 362/398 to the wheels through a Tremec 3550 and a Moser 9" with a nice and flat torque curve. GRAPH (http://www.chevelles.com/showroom/Matt_Leuck/Dyno4small.JPG)

It was my daily driver for a year and a half, and other than a hard brake pedal *sometimes* due to the lack of vaccuum sometimes, I never had any problems.

Good luck!


- Matt

406, AFR195's, RPM Air gap, 770 street avenger, 9.8:1 compression, 1 5/8" shortie headers, XE284. 850rpm idle @ 9.5hg vac. Ssame thing as Matt with the brakes in stop and go traffic but a can should fix that. My stock converter/700R4/2.73 rear combo didn't work to well with this combo obviously when I first dropped the motor. If all goes well today a 6spd will be getting used instead otherwise I'd look at a 3000rpm converter for street/strip or +4000 for serious strip duty.


Nice numbers Matt. You're getting me excited to finish breaking mine in and on the dyno graemlins/hurray.gif