454BB T56 or T10?

[parrotheadmatt87]

Hello all!

I purchased a 68 GMC a while back and I am a bit confused on what to do with my transmission issue. Currently I have a dying 350 turbo automatic. I love manual transmissions and would love to swap one into my truck. My issue is I wouldn't mind a t10 that is built to handle my 454, but my friend said I couldn't put it in my truck due to the big block headers being in the way of the clutch pedal shafts that run to the T10. On the other hand I would love to bolt up a T56 I am worried that there would be difficulty in making it bolt up and work with the 454. Also one concern is the shifter would be in the middle of the bench seat. My brother in law has an 85 c10 and swapped one in his truck and he has a 350. I have found a ton of swaps on SB engines but not many on BB. The more I read the more I want to blow my brains out if anyone has any advice or have been down this road let me know what I need! At one point someone had a manual trans in the truck since the floor board was cut open for the floor shifter. The engine supposedly came out of a 74 c10 and I assume its a 2 piece rear seal which I was told was important on flywheel selection. Please any help would be great!!