360 Heads casting# 3769974. What/When are they from? Any good?

[Clead]

I got these heads in a trade with some other parts, and I was wondering if they are paperweights or worth keeping. The only car I have on the go is my Fifth Ave right now, which has a stock 318 2bbl. I am planning on swapping either the whole motor or the heads/carb/intake over from my DipCop unless these heads are better or at least have more potential. Are those casting numbers any good? They appear to have 1.60/1.88 valves, but I don't have calipers, just a tape measure! Any info appreciated.
Thanks,

[Stoga]

The 3769974 is the 75-76 360 head. It should have the valve sizes you mentioned. 1.88 intakes will fit fine, but a notch in the top of the cylinder is required for a 2.02 intake valve on a 318. They're decent heads, not killer, but plenty fine for a mild application. This is one of the first heads with hardened exhaust seats, so it is worth your time to disassemble them and check for for cracks in the exhaust seats, just in case. If they are in good shape, I wouldn't be afraid to use them. PS: if these heads have the little extra hole below the exhaust flange for emission purposes, you'll have to block that hole if you plan to use early style exhaust manifolds.

[rumblefish360]

Tap the hole for a 1/4 inch allen head screw. Install the screw head flush or slightly counter sunk. Do not remove the hump in the floor of the exhaust port. That hump will actually help flow! DO NOT TOUCH!

[Karl43]

These heads will work great on your car! I have a set of '77 360 truck heads on the 318 in my '68 Barracuda. I did the recessed set screw thing. They pull real nice. Use a mild cam 260 - 270 duration and .430 - .450 lift for nice power and economy. I was getting 18.7 MPG with a 2.76 axle on the highway. That was with 1.88" valves. Car had a nice power band from low end to 6000. This will work nicely with 1.88" or 2.02" valves.

Stoga - I would like to correct you on the fact that the 2.02 valves will work in a 318 without notching the valves. I just rebuilt my engine and had my heads ported and opened up to 2.02's. I am running a stock bore and have 5000 miles on it without any problems.

That is the beauty of the 318. It can take the larger valves without having to notch the bores like the 273. You need to notch the bores to even put 1.88" valves on a 273.

I fugured it out like this. If you go from 1.88" valves to 2.02" valves on a 318, AND you bore it lets say .020 (sometimes .030"). You are increasing the valve diameter .014", which then adds .007" to the radius. Now you overbore by .020" or more you are adding .020/2 = .010". You are increasing the clearance from the valve to the cylinder wall by .003" at .020 overbore and .008 at .030" over. No Problem.

[Clead]

Hey guys, I just read am article on SB head history, and according to it, my cop 318 has 345 casting 360 heads. Which ones will be better to work with? Thanks for the replies by the way. I'm starting to understand all this stuff a little more .

[Stoga]

Good point, Karl! That's what I get for repeating hearsay. I always try to err on the side of caution. Only thing I do wonder about, is how shrouded the valve would be? I remember on most oversized valve swaps I've done in the past, opening up the combustion chamber right next to the valve, would allow them to breath a lot better,especially at low lift. This was done by aligning the head gasket we were going to use, then scribing after applying blue Dychem (sic). Just be careful and don't remove too much, or headgasket seal will suffer! I've seen plenty of J heads with 1.88 intakes installed on 318's, glad to hear the 2.02 is no problem. If I had the motor apart, I'd probably check clearances again though, just for nervousness sake,lol!