There is a guy at our local strip, that in a hurry-last minute-get it together moment ran one 318 head and one 360 head on a 360. He was in it for points and needed to run. Went low 12's in a 65 fish....
Totally sounds like something I would do lol. Go big or go home. That is the Mopar way after all. I'm like Ricky Bobby, I live my life by that saying. Also, I just wanna go fast!
All hardened seat heads are prone to cracking from the mid '70s to now. Iron cracks, aluminum warps. I would skip over them every time for something that's supposed to make power, especially if money had to be spent. My running them- it was more worthwhile having lower CR. Motor woulda been pretty decent had I put 360 heads on it. Might they be worthwhile? Sure. But if you're gonna run 318 heads there isn't really much difference in them. In stock form none are very good or better than each other. A better cam and converter would be a much more worthwhile investment than machining 302s. The smog 360 heads do almost the same job of supporting power as the pre-smog 360/340 heads and the 308s excel in some areas. But those were larger port heads than the 302s that were more meant to be ported and run. Cars, trucks, vans, don't matter- '85+ 318s had 302s unless they had 360 heads. Trucks, vans got flat tappets before TBI though.
The mopar performance clearly stats that on a low compression 340 that the 392 head is worth 25 hp over an X head. Kim
When was that? Probably advertizing because they wanted to promote the new "Swirl Port" head (Nineties?) In stock form a 302 flows worse than a stock L or X head. The EQ on the other hand is a different story.
Since you're going with 302 or 741 heads.. you might as well go with hydraulic roller cam. The heads are already have big push rod holes and retrofit lifters are cheap now. It might save you some headaches with cam break in. A little port matching and Bowl job and a bigger valve will help. Be sure to look out for valve shrouding. All that being said Magnum swap will make more power but cost more.
Well yeah, the 302's in stock form have the smaller 1.78/1.50" valves and 318 ports, so, you can't compare them to X or J heads which never had anything smaller than 1.88/1.60" valves and had the larger 340/360 ports. You can compare the 308's to the X and J heads, and they're about the same on the intake side. The exhaust side is where the "swirl port" heads are better. The 302's are only interesting because they have closed chambers (308's are open chambers like the X and J heads). They're a nice improvement in compression when used on a mild 318, especially considering how low some of those engine are for compression from the factory. But if you start modifying stuff they're still a 318 head, you need to add bigger valves, port work etc and by the time you've done that you might as well have bought an aftermarket head nowadays, you'd have no more money involved and you'd have heads that have a lot more potential. 302's are really only a worthwhile upgrade if you're planning on bolting them on in fairly stock form (unless you can do the machine work yourself), and it's really just about the increase in compression, not a dramatic improvement in cfm for the heads. They were a lot more interesting/useful before there were a bunch of different aftermarket heads available like there are now. Better to just buy a set of EQ's, or even stock magnum heads for a mild build now. Smaller chambers AND bigger valves and better flow.
Hay guy's let us not forget that the guy that started this post is building a 318. Not a 408 or a 360. So the port volume only has to fill that small cylinder. And a 302 head was designed for a 318 motor this head will work fine for what he needs.
Just to make it clear, I'm not bashing the 302 heads. I think they're a good option for mild to moderate 318's. They're a great way to raise compression on a 318 with the earlier open chamber heads, and that will definitely help power. If you have a good bottom end they can be a nice little upgrade without doing a ton of work. All I'm saying is you can't compare the 302 head flow numbers to 340/360 head flow numbers. And like ANY stock head, if you're planning on a lot of machine work- bigger valves, porting etc it's worth taking a long hard look at all the aftermarket heads on the market now. Because unless you do the head work yourself you'll end up paying as much as it would cost to buy a set of EQ's or similar. The other thing is that a set of stock magnum heads would work better than the stock 302's if you're willing to change over to oil through lifters and pushrods and other magnum gear (intake, valve covers, rocker gear, etc). Not as easy as a 302 swap on an LA engine because of the magnum gear, but better compression, flow, bigger valves.
That was 2 years ago. Engine should be well up and running by now. Unless that is, his planning and build progress resembles mine
