If you take the intake off you can drive the front bearing out and carefully remove it from the valley, then re-install. My question is if the front is bad, likely aren't the rest bad also?
Yes I did that in the spring. I did a 455 for my son and we picked up a machined block. I trusted that they installed the bearing correctly but didn't see the hole for the drivers side galley was off. Drove it out and put a new one in. Piece of cake.
I'd also add that this was a fresh build,ran for only 20 minutes. No oiling up to valvetrain, so knew something was wrong. Did your eat itself, that's a totally different deal.lots of debri??
Replacing a front cam bearing while the engine is in the car isn't a bad job. Seems like I used a hole saw on a 2X4 to make an appropriate size driving tool.