C10 SWB LS swap issue (long read)

[GMJimmy]

Hello all. I bought a 68 C10 SWB fleetside with a 4.8 LS/4L60E about 5 years ago and have been meaning to fix a driveline vibration since then. Truck has 2" drop spindles and 4" lowering springs. I also wanted to remove the long tube headers and install cast iron Hooker manifolds to make it a little quieter. Because I need to change the engine angle exhaust work will be necessary too. So now the problem. The engine angle is about 6.5* and the rear end after taking out 2 inch lowering blocks is 2.5*. I added 2 degree shims to get it to 4.5* and lifted the engine to 4.5* which gave me 2* perfect U joint working angles. I thought I had it beat until I checked drive shaft to cross member clearance. If I bottom out the suspension over a bump the drive shaft will hit the top of the cross member loop. I can't lower the engine because of oil pan/cross member clearance (Holley 302-1 pan). The only safe engine angle would be about 6* and shim the diff the same which would result in a 5* U joint working angle. I think a 5* U joint working angle would be ok but I'd like to get it closer to 3.5*. I was hoping to hear from guys that have the same swap to see what they have come up with. Any suggestions appreciated.
Jim