Chevy 402 Big Block, Need Advice

I have a 1939 Ford Tudor with a 402 big block. 700r4 Transmission.
I was tearing into the engine to cam and lifters. I was also going to change the valve springs. I pull the heads because the tops of the valves (tips) has some rough edges. Pull the heads a part needs Probably needs all valves and guides.

My dilemma is to repair these heads or to find a better set that would perform better ?

#6272292 oval port open chamber cylinder heads
#3999290 402 engine block

Edelbrock 0735 Carburetor
Edelbrock Performer manifold
cam spec. int. exh.
adv. dur. 268 280
dur@.050 224 230 lobe sep. 110.0
valve lift .515 .520

Comp Cam # cb xe268h

Any cylinder head advice would be appreciated !!!!

 

I ran the open chamber heads on a 454 (gasket match port job, steel shim head gaskets) with about the same setup as you've got and they worked fine (with TH400). I guess if you can find some in better shape for a good price compared to having them redone go for it, but then again, know your parts source. I believe the oval port heads are good to near 500hp. Check your lifter bores for concentricity, if they're egged out and not round you'll end up with a cam eater, I've got one of those (a 402 that ate two cams on the previous owner) now and am deciding what to do with it. Hope this helps-----Geezer.

 

Nothing wrong with these heads. I ran a set on a 427 in an OT pick up. Only thing I would recommend is to go to the L88 springs. I didn't have as big of a cam and started eating push rods and rockers at hiway speeds just crusing. Talked to the cam company and they told me to go to L88 stuff. Did it and didn't have a problem afterwards for years.

Len

 

That L-88 hardware is some of the best stuff GM put out...

 

Thanks for the information !!!!!

 

Good heads, but if you're running them on today's unleaded fuel you'll want to swap to SS valves, and hardened seats. The L88 springs would also be good!

 

While your at it......
may want to consider the bigger sst vlvs 1.88/2.19
and get the ovet the counter roller rockets
My numbers may be off a little as you need the correct
oval port heads to start with
Do these upgrades and you will be happier

 

oops i meant
over the counter roller rockers
of course L-88 items when availale
I ran three of my BBC chevelles with set ups like this

 

Any relation to the original "Grumpy"?

 

I think edelbrock heads are the best bang for the buck. Hard seats, stainless valves, decent port flow, good springs, etc. Should work great with your intake and cam. Plus you get about 75 lbs. off your front end. The best part is, everything is new.

 

Edelbrock heads I will check that out. what part # ?

 

We're ol' school here...
What's wrong with Deetroit iron???
Oh, I forgot.... BiG blocks are from somewhere in New York...

 

When you start pricing the upgrades to your stock heads, the aftermarket heads start looking really good. If you don't want to go with the aluminum Edelbrocks, you could get a set of cast World Products Merlins. But the aluminum heads are a pretty cheap upgrade for what you're doing.

 

from aother post//////aluminum heads could be you have to watch the port CC runner size as most heads are base off a 454 or hi rpm smaller engine .put to big of a head on the 396/402 you will have a pig.


I do not want a pig

 

You can get most of the aftermarket heads (aluminum or iron) with oval intake ports. At least Edelbrock, Brodix, and Dart make them that way. You can also get standard or raised exhaust ports. Easiest way to figure out what you need is too call the manufacturers tech line.

 

Thanks Larry T

I will do that.

 

Are those cam specs for the old cam, or the new one? Reason I ask is, I have a disassembled stock 454 that has no cam, and if you didn't mix up the lifters, maybe you wanna sell?

 

The Merlin iron heads are built like a brick shithouse. Tough as hell and high nickel castings. Very hard to port but nowhere near immpossible, already capable of no-lead fuel if you buy them as an assembly. You're still lookin at spending good $$$$, but their oval port version will support nearly 700HP.

 

Problem with aftermkt heads and 454 GM heads is. Combustion chamber size. All based on 115-122 cc. The 396-402 heads are much smaller. Usually around 96-97. Use the big heads and very low compression ratio. Like John Deere two cyl tractor.. Run it on distillate..

 

The 6272292 heads are 110 cc, so you might be loosing a little (a little more with composition head gaskets), but not a lot.

Just looked and Edelbrock heads are advertised at 110 cc, Brodix 119, Merlins 119.

 

If it were me, I would not drop the mega bucks on Edelbrock heads. I have a buddy who has them on a 454 and he says his 781's are right there with them. The 781's flow wonderfully! I have 781's on mine. I spent a little cash on enlarging the valves to 2.19 and 1.88. 049 heads are also good. CC is 116-118 stock.

 

We have used a few sets of Patriot's. They are just over a grand and perform well. If you are using stock pistons, choose your cylinder head gaskets wisely. The thinner you go, the higher your compression. Here is a link... https://www.patriot-performance.com/xcart/product.php?productid=14&cat=14&bestseller=Y
Chevy High Performance used a set in their Jan 2008 issue to get 675 HP from a 496. On our latest build we are using a set on our 510 that should tip the dyno a bit over 1000 HP. (procharger F2 inducted) http://www.ccmauto.com/510_stroker.php

 

Most of us here can only shell out just enough for a stock "used" big block... And work with what we have...
That's the way I like it anyway...

 

Are those Patriot heads iron or aluminium???

 

Not a bad price for a set of bb heads.. I almost paid that much for a set of TF twisted wedge heads for a 5.0L Ford some years back... When I had a little extra dough...

 

I've been looking at heads for my chevelle and found most aftermarket heads have too large comb. chambers for a 402. I talked to a Dart rep and he said they could machine thier 308 ( if I remember correctly) castings for 108 cc comb. chambers. The only other solution would be stock castings and thick head gaskets. For my situation ,I was looking for 105/106 cc chambers.

 

By the time you pay for a valve job and have hard seats installed for unleaded gas in an old set of GM heads, you are not too far off the price of having everything new.

They are aluminium.

 

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If it were me, I would not drop the mega bucks on Edelbrock heads. I have a buddy who has them on a 454 and he says his 781's are right there with them. The 781's flow wonderfully! I have 781's on mine. I spent a little cash on enlarging the valves to 2.19 and 1.88. 049 heads are also good. CC is 116-118 stock.

The cast iron heads are at the machine now.
Thanks everyone that posted, That has help my a lot!!

Walt