Here's the deal, I have a Mopar 360 in my Scout. Last year I bought the Edelbrock Multi-port for it. I'm now gettin around to installing it but I want a new motor to put it on. I can get a freshly rebuilt 318 with reciepts cheap! my directions say the injection only fits 340 or 360. so, there must be a difference in the heads. What would happen if I put 360 heads on a 318?

Model years man, we need them to tell you anything!

Model years man, we need them to tell you anything!

Exactly.

I'm going to guess and say you are working with the old LA series small block since you say it will fit a 340 or a 360. In general terms the heads will swap, but the intake ports on the heads of the 340 and most 360s of the 70's era have larger ports. Into the 80s the heads will be the same except on some oddball emissions engines, if I remember correct. Before doing anything I would look carefully at the intake ports on your EFI intake manifold. You can bolt it onto just about any non-Magnum small block, but if the ports are too small you will loose whatever flow you had and cause a bunch of unwanted turbulence. I can only guess what this would do to tuning a EFI setup, but I'm sure it won't help. There are several port designs used throughout the years, but most are similar, just varying sizes. Take careful measurements on the 318, if they are pretty close you should be able to run it. If not, use the heads off your 360. Depending on the heads, you could lose or gain compression, but as long as you aren't working on some dome piston'ed drag engine, you should be ok swapping them. If it were me, I'd just rebuild the 360. The longer stroke makes for some nice low end torque with the right cam and "there's no substitute for cubic inches". Well, except for forced induction, but anyway, check everything closely and you should be ok to swap heads but it's up to you if it's a good idea depending on your engine and the heads you are putting on it. As for the the EFI setup, it may or may not work well on the smaller engine due to the 318s smaller size. Check with Edelbrock and make sure it can work on a 318 or if it can be tuned enough to work. Just my .02

I've never had a 318 before I've always had the 360 in my scout. If it's that big of a low end loss I'll just stick with the 360 and get it rebuilt. Thanks

I wouldn't say it's a huge loss, just a step backward. 318s are great little engines that can run a long time if taken care of and run a surprisingly long time if not taken care of. i just feel that if you have a 360, you might as well keep the 360, especially when you consider all the things you will have to re-do in order to swap in the 318. 360s and 318s don't share the same balance, so you are either looking at a new torque converter or flywheel or at the least, welding on some weights. The balancer is also unique but that should come with the engine. Also the passenger side mount is different so that would have to be changed. I've done a few 318 to 360 swaps and there are a few hidden little details that most would not think about until they hit a brick wall. It's still a lot simpler than swapping to a big block though, lol...

you can put 360 heads on a 318, but the compression ratio will drop a bit, so use really thin gaskets