SHAKERATTLEROLL

You can go here and take a look around to give you an idea of what is out there.

http://www.gmpartsdirect.com/results...ges=1&pkgid=69

Durango_Boy

Thanks Shakes...man that stuff is expensive.

SHAKERATTLEROLL

Well you do not have to purchase from them lol. I just meant it for info.

I would jump in but I have just messed with the Mark IV. You know the old stuff lol.

Durango_Boy

Oh I know, I was making note of all the casting numbers. I was just amazed at the prices. I know that's just what heads cost, and I'm kind of new to that since I reuse old stock heads and have them machined for my purposes.

Jughead

Be careful with those newer casting numbers.

http://www.chevymania.com/partsid/pa...p=head&block=B

I think maybe, Chevrolet's newer (post '80) oval port heads are actually peanut ports.

My 454 block came with 14092360 heads and they are peanut ports although they're listed as "oval ports" in the link above. Certainly not a HP head.

sxr6

Yes above..
My 86 454 came with 045 says "says HiPerf "
but certainly aren't, they were peanut port ovals!

14081045 454 78-87 Oval Port Open chamber

Durango_Boy

So I need to make a list of head castings that were in the 110 CC range, open chambered, and oval port? Can the opening be ported out much on these kinds of heads?

442olds

Ok here's my input, find a set of these heads or something similar 3933148. They have 112cc chambers. I clearanced them to 39cc dome pistons from JE. Chambers were 114cc when finsihed. I am also running 6.535" long con rods. This setup in a 427 yeilded an 11.75:1 compression ratio. I was using a Comp Cams Hyd roller from their Gen6 series of cams, it was the XR294HR, this is a very decent street cam. It made a ton of power in my 427 and it should be even better with a few more cubes. It likes lots of compression. This cam bled off enough compression down low to let me run 93 octane without any problems. I also had a very tight quench height, .035". If you run with a lower dome size, say in the 10~20cc range you should get your compression down to around 10~10.25 static. Using the cam I suggested your Dynamic will be around 8 which is perfect for an iron headed BBC on pump gas. Getting your timing right will be critical however.

Currently I'm running GM Perf Parts Roval Aluminum heads and 12:1 with the XR300HR cam. Still works great on 93 octane, but I'm controlling my timing with a msd billet distributor through a Megasquirt computer and out through a 6a box for more precise timing. It really helped to be able to add more timing down low for idle and crusing.

Also go ahead and upgrade to the beehive springs. The hyd rollers are heavy and they also hate heavy valve train. the beehives are nice because they reduce a lot of valve train weight. CompCams Part number 26120.

OH yeah, the previous owner ported the heads, the intake measured 165cc and the exhaust was 116cc. he matched it to the Felpro gasket as well. valves were 2.18int/1.88exh.

Durango_Boy

How about these? With 100 CC chambers, can I run stock pistons? What will the comp end up at with stock pistons and these heads? I can get them cheap.

10141279...96-up...oval..CLOSED.."Vortec 7400", 100cc chambers

Little Mouse

Edelbrock claims 9.2 comp with a flat top piston and 100cc
chamber. if you have 87 up dished piston 8.8 with 100cc
chamber.

Durango_Boy

Whatever piston is in a '99 454. What if I deck it?

Little Mouse

I don't know anything about the later big blocks, I put that up as
a guideline on what a 100cc chamber will do on a 454 with flat top
pistons. If you have to deal with dished pistons looks like comp will
still be hard to get.

gmg1977

I went with the hi-perf 118 cc heads with the huge rectangular ports I believe they are the 890's cant remember off hand I think GM made them in the early 70's. Ill have to check my info. Anyway I went with the SRP 18cc domed piston with thin gasket and I got my comp up to a little over 10.2. I didnt want to go to 11 and 12 because I still wanted to run on pump gas. Im hoping to get at least 500 hp out of it when it goes to dyno at the end of the month. I'll post performance numbers when it comes back.

TheSkunkWorks

Just a reminder to keep in mind the overall combination. Milder cams build more dynamic compression than wild cams, so definitely keep the static CR down under 10:1 if you're not going to use a cam with lots of duration. The inverse is that you can run more static CR with the wilder cams, but the drawback is driveability issues and poor performance in the low to mid range rpm's you must live with on the street, and the very real potential of detonation near the top of the HP curve on pump gas.

Also, the better the heads flow, the less cam required to do the job, but make sure you don't go overboard with port size and kill port velocity. For a 454 street engine on pump gas, rectangle ports ARE NOT the hot setup. Unless you're revving to the moon, the big ports really don't come into their prime until about 500cid. (OMG, did I actually admit that?)

Advise you talk to CompCams about their new XFI series of hydraulic rollers that use beehive springs before commiting to your final combo. (Those beehives make this series more affordable.) If the lift numbers seem on the high side for you, you can always use 1.6:1 rockers...

Most of all, keep asking all the right questions until it all makes perfect sense.

Durango_Boy

I'm still lost when it comes to all of this. I have a loose handle on small block combinations and then I jump into big block and it's all greek again.

The main points to consider:
-Low RPM street motor.
-I want to keep stock pistons.
-Mild performance cam.
-Shooting for a comp of 9.25 0 9.50.

Thanks for the help everyone.