Im ******* DONE with the 289! Short block suggestions?

So I have decided the 289 in my mustang has gotta go - I need to upgrade! I want something that will work well with the TFS heads I put on the engine just last year - they are 61 cc combustion chambers with no porting or polishing work done on them. I have been looking at some 347 roller short blocks, anyone have suggestions? Looking for the most bang for the buck, pretty much like everyone is! Any one have some short block purchase success stories? Any recommendations? As always, any help is greatly appreciated!

the latest is excess crankcase pressure and overheating problems and leaking coolant A LOT. the leaking part I am pretty sure is just frost plugs that have corroded away - at least 2 of them - but the crankcase pressure I am not sure of. I have to pull the engine to get at the frost plugs (if that is the leak problem) so I am just gonna go with a roller, just dont know what size. The engine was overheating a little even before it started leaking, so I am not completely sure what that is either, but I have been debating on a new engine for a while, and its time to act!