Swapping 200 r4 for a th300

[ChevyHeaven]

I'm actually doing a full engine and transmission swap in my 86 cutlass. I'm ditching my old 307 and 200 for a 350 and th400 out of an old 72 cutlass.
The thing is I got the engine and transmission already in a 85 regal, drove it around for awhile before maki g the decision and drove great.
I'm I the process of rebuilding and preparing to drop the new engine and trans but new questions are coming to mind (last minute of course)
The guy obviously didn't know much about cars in general, his brother did the swap for him so I got little info out of him.
I'm seeing alot of talk about the 400 not matching up with the crossmember in my cutlass but...seemed to in his Buick? I'd hate to find out the answer to that question in the middle of putting it in.
Also, the driveshaft, does it necessarily have to be machined to a certain length to fit or could be hAve just used to one from the 72?..and if so...what then?
Any little tips or info would defiantly help. I'm doing all the research I can and part of that research is this forum.
Thanks.

 

[Evan11]

Swap all the parts from the regal to your cutlass. Use the crossmember, driveshaft, etc from that regal.

 

[ChevyHeaven]

Well that's kinda the obvious answer. I realized the 400 won't line up with my frame like my 200 did. Looks like I may have to drill the hole an inch longer, anyone have any other ideas? Hate to start drilling the frame if there's another way.

 

[jociha]

The difference in lenght between the two is 1/16 of an inch so maybe a bit of reaming is all that is needed.