I Have a 73 454 with stock cylinder heads. I'm trying to decide between having these heads ported, etc and buying aftermarket performance heads. I would like to get between 450 and 500 HP after I get a better intake, cam, etc. Any help would be appreciated. Can anyone recommend a source for either?


[Modified by blunsford, 2:19 AM 9/11/2003]

 

Well, I like the Edelbrock aluminum heads I put on my 71 454. I got the 100cc performer heads which bumped compression to about 9.5:1 (stock was 8.5). You can find some info and dyno graph on my webpage.

 

Your 049 heads are excellent stock cylinder heads, and actually the preferred stock large oval port head as far as flow numbers are concerned. Their major drawback are the large cc chambers which yeilds lower compression ratios 122cc if I remember right. The 049's can be excellent heads with larger valves installed (still debating this myself), but would have to be milled in order to get any sort of decent compression ratio out of them. The edelbrock RPM oval ports are probably the way I'm going to go, not so much for the flow increase as it is for the weight loss but they will raise the compression to an estimated 9.1:1 on an LS-4, which gives a lot more cam choices. A lot of your choices are going to be determined by your intake choices which are extremely limited by the stock hood. Basically your intake choices are stock, torker2, or 68-69 L-36. With an aftermarket hood such as an L-88 you have a lot more choices.

:cheers:
Pat Kunz

 

The heads you have are actually pretty good. There is no doubt you'll pick up power going to an aftermarket head as well as shed 80lbs going to aluminum, all depends on what you want to spend. You should have no problems making 500hp with the right cam and intake on your Big Block much less having and extra $2,000 oin your pocket.

:cheers:

 

Thanks for the great info. There's a racing garage that does head work not far from here. (There's a racing garage on almost every corner in Indy.) I think I'll call them and get pricing.

 

You have several ways to go here, as these guys have pointed out. Now I am not familiar with the '73 454 engine, but if its low compression then you will be smart to limit yourself on cam size. As you may very well know, a real big cam and low CR is going to stink for making power.

This was my dilemna. I have a late model Gen VI 454 that was very fresh when I purchased the car. Problem was with the stock GM iron heads it was only 8.75:1 CR (118cc head). I needed a way to bump CR without swapping the forged pistons in my 1000 mile motor. The Edelbrocks like Zwede runs were a good option. I decided on the AFR 305 head and had them milled to 108cc which puts me right at 9.5:1 CR...perfect for pump gas. I run a small cam (230/230 hyd. roller), but did decide to get the L88 hood so I could have some decent intake choices (went with an Edel Air-Gap).

Even with "low compression" (at least by hot-rodders' standards) and a small camshaft, my engine puts out over 510hp (up from 390hp before)...and I'm only spinning it to 6000rpm. This is a very mild BBC. A little bigger cam would probably give me another 25-30hp (and move the power band up in the rev-range a bit), but again, with the relatively low CR... I was nervous about going too large. Plus, this car idles and cruises around like grandma's car... til I lay into the loud pedal. It's incredibly tame. I've had this new combo together for a couple of months now, and I am still amazed at how great it drives under all throttle conditions.

I don't know how much your 049 heads can be milled to bring up compression, but that will have a direct effect on how big of a cam you want to try. If you can get those heads ported to flow good #s, and get the CR up so you can run a decent cam without losing streetability, then that is always a good option. :)

 

Hey blunsford - pick up the latest edition of Corvette Fever........Front cover article on stock BB heads vs AFR alum 305's. GREAT READING
:thumbs:

 

I would have to agree with the small cam suggestion.You'd be amazed what power you can build without spending the bucks on heads.A set of headers,duals and around 210-220 degrees of intake duration should get real close to 450 hp with a BB.Also note,a 110 degree LC cam will help make the engine think it has more compression than it really has.Keep the stock intake for sure if you run on the street.


[Modified by The Money Pit, 8:10 PM 9/11/2003]


[Modified by The Money Pit, 8:13 PM 9/11/2003]

 

Thanks again everyone for the great info. It is appreciated. With small blocks it was all easy. I feel like I'm back in kindergarten starting over again with a BB. :_dupe:

 

Hey, don't get discouraged. I was in your shoes not too long ago, but have learned a TON over the last 6+ months and was able to make a very informed purchase of a combo that has worked great.

You'll be able to do the same thing, and learn a lot in the process. That's half the fun, I think!

Like you, I've been running smallblocks forever (mostly forced-induction SBF's) and this was my first BBC venture.

Good luck!

 

I have a set of 3946074 aluminums that are about to go to the machine shop to be cleaned and crack checked. Several people have asked if I had done that when we talked about selling. I live 3 hours from you...if you are interested. If not, that's cool. Though i'd offer. :cheers:

Weasle :cool:

 

Let's talk cost. I have a set of 73 049's that I reworked for the engine rebuild. First to go to a higher lift cam you need to do away with the exhaust valve rotators as the stock valve springs are really only good for .500 safely. A new cam will need new springs for the right pressures.

So..... the big valves $125 on ebay and these are Eaton stainless. New springs retainers and locks about $150. New valve guides for at least the exhaust (these are 30 year old heads and at leat 1 or more are burnt or wallowed out), $20/guide. Shims and exhaust valve rotator eliminators, $75. Mild porting, milling them for trueness, 3 angle valve job and all the labor you will have $1200 into the heads.

When you add up the cost compare what you will have into them to a set of new GM performance large oval ports or even Edelbrock heads. Not a heck of lot of difference and they should flow better.

Remember the old saying - fix the top end and very soon the bottom end will go. Higher compression and the old rings take a beating. All in all plan out your attack, costs what you want and how much you have. Speaking from experience that a total rebuild with 9.5CR all new parts, head work etc you are looking at $3500 to $4000.

Best of luck in what you choose to do.