ok, so my buildup is coming along nicely now. I acquired a set of D0VE-C heads, mild port and polish. Edelbrock Perf RPM dual-plane intake. Edelbrock 800cfm, .030 over SpeedPro pistons. The cam recommended is the 34-253-4 magnum. heres the cam spec card page

http://www.compcams.com/information/...umber=34-253-4

does this combo sound like it will work? im basing it off of the Edelbrock Package. They got 469hp with stock heads. So i thought with mildly ported heads and a bit bigger cam i could break 500hp.
Tell me if im way off in my thinking here guys. this is my first build so i need all the help i can get.
thanks,
Andrew

 

You sure those were stock heads?

 

I think that the cam is a bit much for ported iron heads, some times bigger is not allways better. Eric

 

With a cam that big you are going to need a high-stall converter if it's an automatic...probably in the 3200-3800 stall range minimum. If it's a stick you'll need 4:10 gearing or even steeper than that if using tall tires (over 31-33 inches tall). Also with a cam that big you'll need to bump your compression up to higher than what you can run with pump gas, I'm guessing in the 11.0 to 11.5 :1 range. Ask the cam Mfg. what they recommend. Deen

 

I looked at Edelbrock's specs on that 460/469hp engine. They didn't specify which heads were used, but the valves were 2.224I, 1.744E, 95cc combustion chambers and roller rockers. Peak hp was at 6000rpm.

DOVE heads use 2.08I and 1.65E valves as stock. A mild port and polish on dove heads will let them flow 160cfm on the exhaust, maybe even 175cfm if you go to 2.19I and 1.72E valves. I think any lift over 520-525 will be wasted with mildly ported heads and stock valves. The heads just won't flow that lift. You need to get the exhaust to flow 180-200cfm with c/r of at least 10.5:1, preferably higher, to use that cam.

Another consideration will be rods, the stock ones aren't recommended over 5500rpm and with one missed shift you'll easily see 6500rpm.

As Deen pointed out, that cam doesn't start to come alive until 4000rpm. With even 4.10 rear gears and a 3800rpm converter, you won't be locked up for street driving in third gear on a C6 and that'll fry your trans in quick order.

Unless you plan to spend some serious money or effort on your heads, or use aftermarket heads (not that much more expensive than doing iron heads right), I think that cam is way too big for your application. And a 800cfm carb with that cam will just be a starting point.

 

I thought Edelbrock used stock heads in that combo. In another combo they used their heads and the HP jumped up to 506.

So go with a little bit bigger valves and a little less cam? I did tell the guy at Comp that I wanted to stay on pump gas. Now I'm confused as to what to do. Also in going with a smaller cam will that 800cfm be too much? It has a C6 by the way and i was planning on a stall around 3000, with around a 4:11 gear.

Is 500hp still out of reach then? I at least wanted 460hp, but if you guys think I'm wasting my time with these heads then I'll go with aftermarket.

Thanks,
Andrew

 

500hp should be obtainable with the exhaust WELL ported, larger valves, roller rockers, headers, a good exhaust system and 800-850cfm carb. Exhaust ports are the most limiting factor in a 385 and need lots of help. That cam is very wild for a street truck considering what you'll need to run as a converter. A 3000-3200lb street car running that cam a world apart from a heavy truck. Most aftermarket cams from Edelbrock and other non-cam grinders are car, not truck oriented. Talk to a couple of cam grinders and get their input. They'll take your gearing, transmission, tires, weight and converter into consideration when making a recommendation.

 

I did give the guy at CompCams all the info on my car and thats what he recommended. According to NADA giudes, my car weighs around 4300 lbs.
I know this is a truck forum, I had one when I joined this site and hope to find its replacement soon.
Andrew

 

The cam is a little big, maybe they used that cam in anticipation of using the aftermarket heads?? Thats almost as big as the cam I have for my mustang engine, and its a 3000lb drag car.

Also the test was probably a dyno room engine, never meant for a vehicle.

500 is possible, but like was said before lots of work on the iron heads are going to be needed. And for about the same cost you can go aftermarket aluminum.

Also you might want to look at a victor intake vs the rpm if you are going for that power level. The carb is a good starting point, though the holley hp series might get you a bit more power and tuning room, but thats strictly a personal choice.

Or you can keep your current parts, choose a milder cam, and make up the 150 hp difference with a power adder.