Brodix RR vs. GM stock big ovals

[Bandit]

I just ordered a set of Brodix race-rite heads for my BB Chevy 402. they have 115cc combustion chambers and 2.25/1.88 valves. The plan was to gain 50-70 more hp. Now I see that my current head casting #'s are GM 336781 and by all accounts the best open-chamber 454 open-chamber large oval port head that GM made. My 454 heads have Manley 2.19/1.88 valves.

I am not changing out pistons, I have Wiseco 5039H6 with a +38cc dome.

So should I send these Brodix heads back or keep them and install them? Am I going to gain any power with the same CR or not? If not, then I don't think the new heads will be worth it. For me, the $1850 won't be worth it to save 50lb of weight, if that's all I'm getting out of these heads. I mostly drive on the street.

If anyone has experience with a swap of this type and has an opinion I would like to hear it please.

[philbay]

I just, less than a month ago. Had to make that same decision. I have the 781 ovals, in my 70 chevelle, and after talking to my engine builder, I was convinced that other than the weight saving, considerable power and reliability can be had with the 781s. I am by no stretch of the immagination, a skilled mechanic.. But if you have the ovals ported,polished,hardened seats. valves etc. You will be happy.. Im sure if you buy the alum. heads, then do the same mods, more power can be had. But dollar wise.. its your choice.. good luck phil

[jski67]

I don't think it's going to be worth it, depending on how well your 781's were done. Have they been cleaned up at all with a good bowl blend after being
cut for the bigger valves? That will help flow...

Although you would probably see a jump in compression...781's are usually around 119cc (although you need to check for sure) so 115 chambers would
bump it up a little.

But to be honest, I think your biggest hurdle is your engine size...a 454 or 496 could take more advantage of the higher flow of the race rites.

What kind of cam are you running? I've always heard a good solid roller can add about 50 hp compared to a flat tappet and that set up usually runs about $800-$1000.

Hope this helps,
Jason

PS. The race rite is an awesome head though.

[ShawnF]

I agree for your motor size the heads aren't going to give you much if any (you will lose some bottom end with the bigger heads) especially if your motor isn't a real high rever but by going to a solid roller and keeping your ovals you will effectively increase your air flow dramatically. This is because the solid roller is able to run both the spring pressure and have the lifter follow the cam profile exactly as to allow the ramp angles of the solid roller to be much steeper which will mean the valve comes off the seat, opens fully, and returns to the seat in a much quicker and efficient manner. The time the valve is open at peak lift is longer than with a tradditional flat tappet cam. This is your best bet but remember it is the total combo that makes power not just good mix matched parts.