Quote:

I can understand the need for a center sump pan but why an LA timing cover and water pump?



To make room for the extended snout on the camshaft. when Chrysler did away with mechanical fuel pumps they also shortened the cam and on the Magnums they shortened the timing chain cover. The pump was redesigned for th enew Magnum cover and won;t work properly on an LA cover.

Don;t forget accesories. You are not likely to want to run the Magnum accesories, especially if you run the LA cover. You may have alignement issues running LA accesories on a Magnum block, just check them when you build the engine.

As for 340 vs 360, assuming both need rebuilt, r both don't, my recommendation is this. Street - 360, strip - 340.

360 has a longer stroke, builds more torque, all else the same. Torque is better for a street car.

340 has a shorter stroke, will rev up quicker and be happier higher up making more HP, all else equal. HP is the ticket for the strip.

Be an interesting dyno test if you took a 340 and a 360, built them the same (compression, heads, cam, etc) and see what they did.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.