Just a thought here FEforME.....i just recently finished up a nice strong street 390FE for a t-bird that is a 2 bolt .... as far as wanting to take it and have it made into a 4 bolt just ask yourself if its really necessary,i have a "decent" cam/compression setup in the 390 i just finished and it really dosent rev high enough to worry about changing to a 4 bolt main.....just tryin to save ya a few bucks on something you might not need to have done.

Good luck with it