[Peepaw]

OK guys, another 1st for me. I picked up a '72 C10 402", and I haven't really messed with the BBC stuff. I have always strayed to the "lesser common" of the Ford and Mopar camp, and last 10+ years, been doing a lot of the LSx stuff...but no BBC.
So, this 402" has been punched .030 over, TRW flat tops @ 9.5:1.
ARP rod and main bolts.
Comp cams 218/224 .500/.500
Oval Port semi open with Manley SS valves, 2.19 on intake.
Crane Gold rocker
Edelbrock Performer RPM
Holley 750 Vac Sec 3310
MSD 6A ign and coil
MSD Billet Dist. and wires
Hooker Headers
Turbo 400
12bolt with 3.73's
Truck runs GOOD. I had to pull carb off (had leak off baseplate), but she has been sitting for last 5-6 years in storage.

OK, my question:
How can I find out what heads I have?
If these heads are "lesser" heads, which route should I go, and will any Mark IV head work. I am asking that because I know the 402 bore size is a lot smaller than the 427 and 454.
What do I want out of the truck? To have fun.....but you can't ever have enough nuts.
Thanks guys.

[Bowtie man]

Post up the head numbers an we will go from there.

[Peepaw]

And they would be where?

[S10 Racer]

Originally Posted by Peepaw

And they would be where?

They are under the valve covers, on top of the head. Should be 7 digits

[cdminter59]

First lets have a look at the id numbers on the pad on the block in front of the passenger head. Then remove the valve covers you will see the head casting numbers. When you find them post them in your thread. The 402 should have a set of closed chambered heads on it. The bad news is even with a set of closed chambered heads and the flat top pistons your compression ratio is around 8.0. A set of KB160 pistons with a .180 dome and a set of 105cc closed chamber heads would bump it up to 9.6.

[454C10]

Most likely a set of 820's. Which are very good heads.

They flow especially well on the exhaust side. The heads are unique, as the chambers are parallel with the head instead of angling from the intake to the exhaust valve. This shape unshrouds the exhaust valve.

I have a set on 820's with 2.19/1.88 valves and they flowed 250 cfm at 0.500" on the intake a 200 cfm on the exhaust. Flowed 265 at 0.550". The chambers are 112 cc. Good for 530hp with a 0.550" lift cam.

If you want to upgrade your engine, get a 454 block.

[Peepaw]

Well, the heads have been changed out, that I know. The longblock was done @ 10 years ago, by the machine shop I use for all my other stuff.
So, they are NOT the heads the 402 came with, but the shortblock IS original to the truck. Stock crank, stock rods, resized and now house ARP rod bolts. Mains carry ARP studs, and pistons areTRW flattops.
WHole rotating assembly has been balanced, new oil pump, TC, etc....Heads have also been ported, but here is the kicker: Only ONE of the heads has been ported. WHat happened was, one of the heads started leaking water from getting a little carried away obviously, so they grabbed another head, threw a valve job on it, and took valvetrain from bad head and placed it on this head.
So, I have one ported head, and one not ported, LOL!
I was hoping I didn't have to pull the VC off to find the numbers, but figured I would.
OK, give me some time here, and I'll let you guys know what I find.
Thanks

[Peepaw]

Originally Posted by 454C10

If you want to upgrade your engine, get a 454 block.

OK, here is the deal about that: The shortblock (402) is rather fresh, with only around 15-20K on it. So, I was planning of doing is, pick up a set of "good" BBC heads, plop them on my shortblock, and let it eat for time being. Probaly even going bigger on the cam while I'm doing heads.

Once I had some fun with the truck, locate a shortblock, freshen it up, then take the heads on the 402, and plop them on my new shortblock (probably do a basic 496" shortblock.
THAT is why I wanted to know if any BBC head will bolt on my 402, so when I went 454" based shortblock, my heads would work on it.

Take for example SBF stuff. You can take a measly 302 Windsor, and place ANY head designed for a 351Windsor on it.

Or, take the LSx stuff: You can take a head off a 4.8, 5.3, 5.7, or 6.0 and any head will work on any of those blocks. HOWEVER, you CAN NOT put a 6.2 head (the L92) on the 4.8, 5.3, or 5.7, because the 6.2 head calls for mininum bore size of 4.00".

So, since I know my 402 bore size is quite a bit smaller bore size than the 454, I wanted to know if the heads interchange, OR if I would run into a problem with valves being way to close, or hitting the cylinder walls. See what I am saying?

[Peepaw]

OK, here are the numbers I pulled from under valve cover:

the 7 digit number:

3931063

I had a hard time reading that 2nd 3, and the last 3, so it might be the following instead:

3981068
Or
3931068
Or
3981063

I also found:
GM4T
and
PA3S (drivers head says PASS, so maybe that 3 is actually an S??? I already put PS VC back on so can't double check it)

Hope that helps guys. Those are the numbers on passenger side head.

[Peepaw]

OK, and it appears I may actually have a different head on drivers side all together

The numbers I pulled from drivers side head, under valve cover, are:
B87
GM6T
PASS
Conv4

Those are the only numbers I could find...so no 7 digit number.

So, what are we looking at guys? LMAO!!!

[Peepaw]

OK, my mistake, there IS a 7 digit number...was just kind of hiding from me on the drivers side there:

It's:
3909802
OR
8909802

Hope that helps, thanks

[S10 Racer]

Originally Posted by Peepaw

OK, here are the numbers I pulled from under valve cover:

the 7 digit number:

3931063

I had a hard time reading that 2nd 3, and the last 3, so it might be the following instead:

3981068
Or
3931068
Or
3981063

I also found:
GM4T
and
PA3S (drivers head says PASS, so maybe that 3 is actually an S??? I already put PS VC back on so can't double check it)

Hope that helps guys. Those are the numbers on passenger side head.

If the number could be: 3931063
Oval Port
1969-70 396
Closed Chamber 100.9cc

[Peepaw]

Originally Posted by S10 Racer

If the number could be: 3931063
Oval Port
1969-70 396
Closed Chamber 100.9cc

That is my first guess (3931063).

From best I can tell, I have one 063 head, and an 802 head. One head ported (don't know which), and Im not pulling intake off at this point, but both heads have a valve job, and oversized intake valves.

From what I gathered, the 063 seems to be a pretty decent head, and the 802 is rather similar, but maybe not as in high regard as the 063??? I found a few threads with guys making pretty good power in 396-468" cube motors with the 063, but not so many with the 802. Granted I didn't do a whole lot of searching, but that is what I have come up with so far.

Any tips/suggestions guys?

[S10 Racer]

Originally Posted by Peepaw

That is my first guess (3931063).

From best I can tell, I have one 063 head, and an 802 head. One head ported (don't know which), and Im not pulling intake off at this point, but both heads have a valve job, and oversized intake valves.

From what I gathered, the 063 seems to be a pretty decent head, and the 802 is rather similar, but maybe not as in high regard as the 063??? I found a few threads with guys making pretty good power in 396-468" cube motors with the 063, but not so many with the 802. Granted I didn't do a whole lot of searching, but that is what I have come up with so far.

Any tips/suggestions guys?

Considering your numbers are correct, both heads are closed chamber and the same cc (100.9) but because one head has been ported and the other was not, the runner size may be different depending on what was done. What are you wanting to do with the motor? That will tell us what direction to send you.

[Peepaw]

What I want is more power of course but my question is: the heads I have....worth a crap? If so then what can I expect out of them on top of a 496" shortblock? Or...r there better stock head options out there that I can boot on the 402" and once the 496" is done plop them on it? On motor...would be nice to tickle 500+....whatstock heads can carry me there