That is all true except the 53 truck bell houseing is not at all cose to being the same as your 49. The 53 has the rear engine mounts cast integeral with the bell houseing. the 49 style is mounted at the front of the engine and the rear of the trans.I have a 49 f1 with a 49 truck block. I used the adapter kit from Cornnhusker rod and custom to put a t5 behind my flathead v8. No problem what so ever.
The t5 i have is from a 93 mustang and I used the tail shaft housing from a S10 so the shifter would line up in the stock location. The clutch disc I used is from a 93 mustang. the whole thig works great. I didnt have to do a thing under then bolt it together and go drive it.