hi everyone, my neighbor has a set of 3931063 and 3872702 big block heads. what kind of power can these support with mild porting/bigger valves? also what do you think is a fair price for them? they both need rebuilds.
thanks,
chris

I would could consider both very good heads.Easy to make 450-500hp with them.Around here a used rebuildable set will go for about $300.00

my stats are in my sig with a set of 702's with 2.19's and 1.88's I thought they worked pretty good.

I used the 063's. Ran low 12's with them with a 4-speed. I bought them as rusty doorstops for $137 and then put about $800 into them for larger valves, guides, machining, porting.....

last set of 063 heads i bought was good enough just to bolt on and run and i bought them for 200 bucks.....later down the road i ported them put the bigger valves in them and ran my car well into the 11's and used 150 hp shots for some 10's.......

for the most part the oval port bbc heads just with porting and bigger valves are good enough for 10 second rides.....i even have a set of "truck" heads on my race car i believe they are the '148 casting and i have done all the work to them porting wise and they have been good enough to run me some 10 second passes....and thats on the engine alone.....

sounds like they are both pretty good heads. i just don't know if they'll do what i want them to do. i'm shooting for close to 600hp if possible with a 454.

my 454 makes well over 600 hp with those ported '148 heads and they are "less" known of the more popular stock heads.......

what might be the hang up that your not sure about?

i'm jsut trying to figure out my whole combo right now so i can make a decision on the heads because if i don't want to buy them my neighbor is selling them in the paper. i only have my block and crank right now so i still have a lot more planning to do.

Isn't the 702 heads the "bath tub" shaped closed chambers? If that is the case (can't remember for sure) but I would think that the 063's, which are semi-closed chamber heads would have greater potenial for horsepower when larger valves are installed and some port work is done.

IMO, the early "bath-tub" heads looks like they have alot of valve shrouding for any decent flow.

What is actually being said here AND none too clear, (IMHO), is that just about all the large oval port heads and even reworked peanut port BB heads on smaller motors will run VERY GOOD IF the compression is up in the good pump gas range!!

Big valves and all the bells and whistles or just the bells and whistles on the stock valve heads...

Most guy's have found out that the BB rect. heads are just too big for most grunt applications in the STREET compression and rpm ranges is all BUT they do have their place on big, "balls-out" motors too!!

Guys get into trouble trying to make good power out of an old 454P/U motor that has flat-top pistons in it when they try to run open chambered large oval heads on it b/c the compression goes in the tiolet!!

GM never made a stock, about 90 cc chambered BB head, so that we could get decent compression out of the old stock, lo-po P/U truck motors is all b/c if GM had, it would be a winner!!

pdq67

Flat tops and closed chambers is about as good as it gets,,,10.5-1, as for me... my 049's 2.19/1.88 served me well,moving over to 781's 2.25/1.88 polished up pretty good. The new motor will fire this afternoon or tomorrow for sure on an engine stand at the builders,then I'll have to wait for at least a 50* day to make the swap,can't wait to feel the torque :D

Bob,you must be pumped :cool:

You betcha Chris,,,got my Moser axles and cclip eliminators yesterday,and rear housing support cover. Almost like a kid in a candy store with anticipation :D

RR, when will it be 50* there? there's snow on the ground here. It looks like another month before mine will be together. Keep us informed and I hope everything goes as planned! Can you say "Ground Pounder?" graemlins/thumbsup.gif