So Im building a 318 magnum block with LA heads. I have both 318 and 360 heads. what is the best to use? And why? Im working on a tight budget.

What are you using it for?
Why not use the magnum heads, since they are the best?
is this a stock 318 magnum block with stock pistons?

What are you using for pushrods and lifters? (b/c those are where most of your problems will be, ie oiling to the valvetrain and preload)

they both have pros and cons

318 head..
small valves with small port/runners
makes better lowend torque off idle,gives up topend flow/rpm,gains a comp bump with closed chambers.

360 heads..
bigger valves with bigger ports/runners
gives up lowend torque,gains topend flow/rpm,drops comp ratio with large open chambers.

remember,only early magnum blocks will be drilled to oil thru the head to shaft mount rockers LA style.

watch the cam also,not all roller cams are drilled for LA style oiling.

whats the plan on how to oil the rockers on your build?

The mag block is a 1994 so does this have oiling for the rocker shafts?Im not using the mag heads because I trashed one trying to re drill for la intake. I know this has been covered before but what pushrods do I need also? The motor is going to be used in my 1947 dodge truck rat rod it is now running with a stock 318 904 combo.It is just used as a driver so I am looking more for MPG than Super high perf.

You can drill horizontally into the rear of the LA heads then angle up to the rear pedestal (drill the angled one down from the threaded area) then T into the sending unit oil fitting passage at the top rear of the block to externally oil the heads if need be and an .080" restriction will get you close. On the pushrods I'd mockup & see what dimention you need first then go from there.

FYI, my 91 pre-mag roller cam engine has oil thru roller lifter with hollow rods oiling the rockers at the same time it oil up thru the LA heads to oil the shaft and rockers.

I am not sure if oil thru lifters and hollow pre-mag push rods would be enuff oil to the shaft mount rockers.

looking at mine it seems to be oiling them plenty but then again it is oil 2 ways.

if I had a JY magnum engine to run a set of LA heads with it oiling the rockers by lifters/PR only I would give it a shot myself.

you could go first on the testing if you like..?

seems to be enuff oil supply to magnum rockers on a pedistal mount.

all of this headache just because you boogered up one head trying to drill it for the LA pattern?

you're leaving a lot on the table in terms of Hp by going away from the magnum heads.

and Magnum heads are cheap. dime a dozen. most of us with them can't GIVE them away!

I may try to call around to a few bone yards and see what I can get a new head for. I cant belive how good the bottom end of the mag looks at about 150K.