My painter is all most finished priming my car and it's my turn to reasemble the front cap.
Would I have a problem if I installed my motor/trans on my subframe befor I assembled the front cap or should I install them after its painted.

thanks

Not necessary, but preferrable to install the front cap with engine/trans in the car just in case there is any flex between the body and frame with the added weight.

With new bushings and everything torqued down, there should be very little (if any) flex issue.

have a good talk with your panter about "masking etiquette."

You wouldn't believe how many posts we see asking "how do I get paint off overspray of xxxx?"
Engine compartments are the worst as far as trying to get overspray off of. Many many nooks and crannies.
The entire engine compatment must be masked off edge to edge before the hood is lowered for painting. Ditto with the inner fenders, and a continuous paper drop to the floor, taped to the inside of the rocker pinchweld. Overspray gets into EVERYTHING.

Personally, I left the front clip off, and completely bagged everything from the firewall forward. Same with the interior in my vert, totally masked, painted with the top down.

2 stage urathane does NOT come off.