Yes, the distributor needs to be changed. LA318 roller motors ('86ish-'91) and LA360 rollers ('88-'92) all had computer-controlled distributors, no vacuum or mechanical advance systems. An appropriate earlier factory or aftermarket LA distributor is a necessary bolt-in.
"Just" a manifold and carb swap? Don't forget all the ancillary parts needed just for a carb swap: throttle linkage, kickdown linkage, accelerator pedal and cable (your /6 throttle is a pivoting rod type, incompatible with the V8 application), return springs and bracket, etc.
If your new motor came out of a truck, you'll need to swap to a passenger car pan/pickup/dipstick.
The transmission is going to be a whole 'nother ball of wax.
Your slant trans won't fit a V8, so a later 904 will be needed. Even a V8 trans from '65 or earlier won't fit the later LAs without a crank adapter. Then there's the linkage- '65s are a multiple cable controlled shift linkage, so for the later 904 to work you'll need to delete all that and install later ('66 and up)Steering column and linkage or factory '66 floor linkage.
And then there's the driveshaft- your '65 uses an output flange that mates to a ball and trunnion joint on the driveshaft; later trans. use a slip yoke arrangement. New driveshaft time.
And the speedo setup changes- you'll need a '66-'67 only speedo cable to mate a newer trans to your stock speedometer.
And Doug's. But neither fit with power steering.
'64-'66 A body V8 manifolds are all the same.
But they're not a direct fit to your proposed aluminum heads.
It's not so much if they'll fit the 360, it's the heads you're choosing. There will be interference that will need to be addressed.
