so i just grabbed a 460 from a friend of my brothers to replace the one in my boat with i was wondering if there were any interchangeability issues between the years of 460 i know some have dipsticks in the pan and some in the timing cover  are all the parts able to cross over or not if not which ones can and which ones cant can i change the timing cover to convert this new motor from a pan dip stick to a timing cover dipstick

im going to be putting my boat oil pan on the new motor and it doesn't have a dipstick in the pan can i swap the timing covers out to make it a timing cover dip stick

...just grabbed a 460 from a friend...to replace the one in my boat... i was wondering if there were any interchangeability issues between the years of 460...i know some have dipsticks in the pan and some in the timing cover....are all the parts able to cross over or not...can i change the timing cover to convert this new motor from a pan dip stick to a timing cover dipstick

1968-1978: Internal balance engines.
1979-1996: External balance engines.
1968-1987: Carb'd engines.
1968-1978: FI engines.

The chances are that your "dipstick in pan" engine is an external balance engine, while your "dipstick in cover" is an  internal balance engine.

Therefore, if you swap front timing covers and oil pan/pump/pickup, do not mix up any other parts between the two engines. Specifically, the external balance engine should retain its external balance flex plate (bolted to rear of crankshaft) and its external balance hatchet weight (the pendulum/spacer behind the harmonic balancer).  Again, this assumes one engine is internal balance and the other is external balance.

If the "dipstick in pan" 460 is 1988 or newer, it is an FI engine which utilizes a completely different top end which will not accomodate a carburetor/carbed intake nor your boat exhaust system. It would be necessary to swap over the entire top end (including the valve train from the pushrods up) to the later engine.

Lastly, while the timing  cover is off it would be a good idea to install an aftermakrt double-roller timing chain. NOTE: The 460 FI engines (1988-1996) already have them and are good to go while the 1979-1987 carbed 460's have a retarded chain set and should be replaced.

LO

...about motor A it came with the boat when i got it. and from what i understand came out of a 70s van the heads say d3ve a2a and the block has DIVE - something stamped in to the passenger side so im not sure were it really is from. is there a way to tell by looking at it weather it is internally or externally balanced

The external balance engine has an external balance flex plate (which has a weight welded to flex plate) and an external balance hatchet weight (the spacer behind the harmonic balancer has a pendulum aka "hatchet weight" (internal balance is just a cylindrical sleeve w/o the pedulum weight). 

Also, the external balance 460 engines use block number D9TE-AB.