I bought a good running 454 out of a motor home. It is cast #361959 (small deck). Heads are 346236 oval port 120 cc chamber, 225/116 cc ports. Although motor ran good I took the heads off to see if it was bored & check for ring wear. It has 40 over pistons. This rebuild is quite fresh, so I do not want to mess w/ the bottom end. My question is what cam should I run & are these heads gonna be alright to run in my 71 Camaro w/ a 4speed. If I use these heads what cam is best to go with these. Thanks guys.

I have been told the 268H is a good all-around cam for a low compression 454.
If you want a few extra horsepower and improved throttle response do a little pocket porting on the heads since they are off.

-236 heads are peanut port jobbers and I bet if you haven't already cc'd them so the numbers you posted are correct, that I bet they cc down around 200 cc's intake port size.

Hope I'm wrong..

And, yes, a good old CC 268HE cam will be a dandy!

If they are indeed that small, pick up a set of old -206's that should be right at 96.+ to 98 cc's chamber sized and that will have true large oval ports!! Then use Mr. Gasket .020" thick steel shim headgaskets to bump the CR. up like a 1/3rd of a point!!

True large oval ports like say 255 to maybe 260 cc's............

pdq67

If I do find some heads w/ bigger cc intake ports is the 268HE cam still a good choice? Also what exactly is pocket porting (same as porting & polishing?).

How would these Summit heads work for me.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D152125&N=700+4294925232+4294838998+4294867081+4294908216+4294840133+4294867028+4294867078+115&autoview=sku

Also is an edelbrock 750 too much carb for this.

Thanks.

Pocket porting involves cleaning up the casting flash and machine work in the bowls which is the area where the port turns toward the back of the valve. There are generally good size ridges that hurt flow. Porting involves enlarging and changing the shape of the port for maximum flow and is generally reserved for racers or street guys with deep pockets. Those Summit heads are going to want to rev pretty high to get good power, I'd look for some oval ports that are compatible with your pistons. Flat tops will want a closed chamber head, open chambers for domes. If you're staying with 454 stroke, it may not be worth having bigger valves put in the heads, just do the pocket work and get a good valve job and you should be good to go.

If I do find some heads w/ bigger cc intake ports is the 268HE cam still a good choice? Also what exactly is pocket porting (same as porting & polishing?).

How would these Summit heads work for me.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D152125&N=700+4294925232+4294838998+4294867081+4294908216+4294840133+4294867028+4294867078+115&autoview=sku

Also is an edelbrock 750 too much carb for this.

Thanks.


Those heads are a bad choice for your application unless you change the pistons too. Not only are they too big, but have raised exhaust ports. Header fitment could be an issue with them. You didn't mention what kind of pistons you have other than them being .040 over, are they flat, dished or domed? IIRC if you do have the peanut port heads, your best bet is to find better heads. That Edelbrock carb should be ok.

I ran the comp 294 S solid cam. Very drivable, and will make that 454 grunt.

Grumpy,

A 294 cam in an 8.5 to 1 and probably more like 7.9 to 1 CR. 454, give me a break!!

That said, I'm glad you liked running it!! My about 9.5 to 1 CR. 406 SB was a dog w/ my 292/230, .480" lift cam w/ my M-20, 3.31's and 26.5" tall tires until she hit about 3,000 rpm!! After that, HOLD ON!!!

S,

Read me again!!!!!!!!!!!!

Get her up to say like 9.3 to 1 CR. doing this and a CC 268HE or an old Isky 270 Mega cam will make it a torque monster!!!

Heck, Erson's HI FLOW AH is a dandy here too!!!!!!!!!!!!!

Take your pick!!

pdq67

spyder, to pick the right cam for the application, compression is vital info. a dished piston is going to need a total diffrent cam compared to a domed LS-6 piston.
I have open oval heads and chose the domed pistons and a CC 265DEH for a nice flat power curve. I sacraficed a lil on the peak power for more low end and more area under the curve..

My limited knowledge is subjet to the critics..

They are 40 over flat-tops. Are the BBC heads interchangeable like the SBC heads? Do I want rectangular or the true oval ports. I'm gonna start looking around to find a decent set. Thanks for the help so far guys.

get the Hi-Perf Passsenger car oval ports. They will support 550 HP stock with a good valve job and an hour of bowl blending. The square port heads get big bucks and really do little below 5000 RPM. I saw one test done several years ago, and the big oval port heads made MORE power on a 10:1 454 with a moderate cam up to 5200RPM, then the square ports did a bit better up to 6,000, the the oval ports gave up 35HP at 6500RPM. But the oval ports made 3O more HP at 3500RPM. I saw decent, rebuilt oval ports this weekend at the Englishtown swap for $3-500 and good cores for under $100 a pr. Lotta guys swear by the open-chamber 73-75 heads because the open-style chambers really unshroud the valves compared to the older bathtub style closed chambers.

Read my posts some more b/c I'm trying to tell you how to get your CR. up the easy way.

Old, true closed chambered, large oval heads like the -206's and others along w/ .020" thick shim headgaskets and a 268 to a 272 cam, 1.75" dia., 4-tube, long headers and go!!

I have a bare set out in the garage I bought several years ago for $75/pr. over at Super Chevy in Indy...

pdq67