401 swap into '62 1500

[NArias3]

Hi 6066'ers-
I'm the proud owner and driver of a survivor 1962 1500 Custom Cab, Long Bed, Big Window 305D-propelled beast. Here's my first post...and probably one that's been discussed previously. I'm acquiring a 401 non-M out of a fire truck and am considering swapping into my '62. Trans is Hydra-Matic.

My biggest concerns are:

1) The 305D flex plate bolting up to the 401. Is the crank flange distance from the block rear surface the same between the two? And, is the crank flange bolt pattern the same?

2) Does the exhaust manifold of 305D bolt up to the 401 without port flow restriction?

3) Any other unforeseen issues with this swap.

The experienced replies to these and any other concerns you can offer will be greatly appreciated. Thanks, Nick.

[FetchMeAPepsi]

I can't help with the engine swap, but welcome to the club!

[bigblockv6]

Everything you want to transfer from the 305D to the 401 will work, you may want to consider using the 401 exhaust manifolds as they have free flowing passages. Another issue is if you want to use the 305 timing cover housing, if you do then you will need to discard the 401 3 piece gear drive and replace it with the 305 double roller timing chain and sprocket which will also require capping the center idles shaft hold with a 1 1/8 expansion plug