Hey guys been quite a while, i bought an 87 and im building a 350 for it and need help selecting the cam. Heres specs i got so far

3970010 350 2 bolt main block bored .30 over
882 casting heads 76cc 1.94/1.50 valves
was told its 9.5.1 comp ratio
headman long tubes
holly aluminum high rise duel plane- unsure of exact model
600 edelbrock carb
plain jane 700r4 no aftermarkrt stall

I have no knowledge whatsoever about cams so i need some help
thanks in advance

 

Hi!

a little more info would be nice.

 

sorry had to edit

 

well if its 9.5 CR then either the heads or the decks are milled alot, or the pistons are definitely not dished anymore


need more info

 

I think they just flat head with vallve reliefs

 

With 76cc heads, .039" head gasket such as FelPro, pistons .045" in the hole like most are, and 5cc valve reliefs, I come up with 8.4:1 CR.

With smogger compression like that, you need to keep the cam small. One of the Comp "Dual Energy" series, or the XE256, would be about right.

 

sofa's mention also goes with your stock stall speed.
That would give you a solid basic 350. Low RPM cam, smog heads, nothing special about it except for it being shiny and new. Expect in the range of 200-250HP - nothing to write home about.

If you wanted more HP, look at better heads, a better cam, and a bigger stall speed. That sounds like a lot, but it'd better match your long tubes and intake manifold...

 

I'm guessing this is what you would call a "budget build" given the smogger heads. With flattops you'll still have a hard time hitting 9:1 compression, but that's OK- I've built many cheap 350s very similar to yours back in the day. Keep the cam MODEST if you want decent power with low compression. Low compression and big cams don't play nice.

With those flattops try to use a thinner head gasket than the typical Fel Pro .039" "rebuilder" head gasket to get as much compression as possible. I've have very good results lately with the GMPP .028" composite head gaskets and the price is right, too- only $35/set from Scoggin Dickey (sdpc2000.com) and other places.

With that gasket on a 350 bored 30-over, typical flattop pistons you're looking at about 8.8:1 compression.

Back many moons ago my "go to" cam for a mild performance 350 like that was the Crane Energizer 266. It's got 210*/210* duration on a fairly tight 110* LSA- does a GOOD job keeping cylinder pressures high with a low compression engine. That equals TORQUE. Now, it'll be pooped out by ~5000-5500, but so will your heads, so it's a good match. And it'll have plenty of torque down low to work against your stock stall converter.

These days there are better cams on the market- I'd look seriously at the Comp XE256. Similar specs but with more exhaust duration (which will help with your weak stock exhaust ports) and more aggressive lobe profiles.

And make sure you have a decent flowing exhaust behind those headers. I'll say that 300HP is not at all outside the realm of possiblity. I used to turn bottom-basement 14s with combos similar to that, assuming a good launch.

 

Allright thanks guys,the XE256 dont sound to bad