I think it would.  Look at all the GT500's, Vipers, etc. out there running very low ET's and making 1000+ hp.  All those cars have the OEM version of that Mag T-56.

However, thinking about the cost and thinking about how consistent it would be, I still think you should stick with the slushbox.

A T-56 behind an FE takes a good bit of work just to get it to bolt up unless you're willing to go with all-hydraulic actuation.  You're gonna be in at least $800 just for the bellhousing itself, as you take a Quicktime FE/T-56 bell and make it SFI approved.   I don't necessarily know if a Soft-Lok or similar would work for you, you might have to go with a hipo twin disc.  Either way, you're looking at $1200-$1300 at least there. 

The trans would probably run $4000+.  In a heavy drag racing application, I'd be tempted to face plate the gears or pro-shift them. 

It's dry.  Some guys do it on a lathe, some guys do it on a crank polishing machine. 

As for the rod journals, yes, it's possible for an FE rod journal to be taken down to a BBC size.  However, a lot of crank grinders can't or won't, because you end up grinding a lot more than journal surface.  You have to widen the journals as well and that eats up a lot of grinding stone.

Find out if your guy can do it first off, then get a price.  It will be more expensive than the old 10/10 deal.

It's for sharing information but there are some things that we don't feel like sharing, or just don't have the time to sit down and type out a book. We shouldn't be called out for that.  Plus there are instances where we just don't want to put up with the drama, cause we all know that our uncle Roscoe's cousin's roommate knows more than we do.

There's a lot more to it than flow.....velocity is just as (if not more) important.  Just going off of the numbers laid out before us, mid 260's at .050" duration will get you a 7000 rpm hp peak with 445 inches and hitting at around .700" lift. 

Do you know the port volume?  I would imagine it's on the large side...

With an 80% intake/exhaust ratio, you don't need a big duration split....3-4° will work. 

If I were doing something like this and weren't wanting super stock valve lift, I'd use a pair of Comp RZ lobes, 264/268 @ .050", .757"/.760" lift, and shorten the LSA up to help the exhaust scavenge the big intake port.....probably a 107-108 LSA.  The shorter rod will help you here too, but I imagine that intake port is HUGE. 

That's where I would head.....your mileage may vary. 

Good luck to you Barry! 

I think for the price of the sleeves and all the machine work (plus the probability of doing it all and having a failure), I'd save my lunch money up for an aftermarket block, or run a stroked 390. 

Yep, turn 'em down.  I could see how you would have no oil support towards the bottom of the cam journal if all the oil was coming in from 12:00. 

Every side oiler and every aftermarket FE block lived/lives just fine with the bearing holes lined up at the 6:00 position.  Sometimes I will clock them at 4:00-ish position, but I continue to wonder if it's necessary at all. 

Make sure your cam spins freely in the bearings when you install it.