Yes go with a trans crossmember especially now that you've made a long driveshaft. Make sure it's balanced, these things can go crazy if out of balance. Don't know the max length for a driveshaft but do know if she's to long can cause catastrophic failure. Be safe


It's easier to get forgiveness than permission!
1946 1/2-Ton Chevy
1953 Chevy 3/4-ton Factory Stakebed