I have a vortec 4200 mached up in my 54. I bought some mounts from Chassis Engineering, drilled and bolted to the frame. The factory mounts on the engine probably wouldv'e worked, buy I made my own from plate and used Ford Taurus rubber mounts.
http://s1074.photobucket.com/user/w...mp;_suid=1465319684703008745591035813743 I have a 5 speed trans bolted to it. I'm using a 3" drop tranny crossmember which will bolt to the lower flange of the frame.
The crossmember at the front of the cab doesn't need to come out, but for servicability I'm going to remove it. I don't want to have to pull the whole drivetrain for a transmission problem.
My plans are to use a 6" drop crossmember, (a 4" may work) bolt it to the frame. I'm going to split it in the middle and weld in a tube coupling. I may add some gussets to the bent areas of the crossmember for added strength.
Trailblazers and Envoys are very common in the sccrapyard now. Finding a complete vehicle with everything you need should be realitively inexpensive.
http://s1074.photobucket.com/user/w...amp;_suid=146531918688708243237331574429It fits nicely in the frame rails.
I trimmed the front crossmember slightly. This wasn't really necessary, but it made my install easier.
http://s1074.photobucket.com/user/whitedog76/media/0429152118a_zpsbsxnrqvo.jpg.html?filters[user]=125630029&filters[recent]=1&sort=1&o=0#/user/whitedog76/media/0429152118a_zpsbsxnrqvo.jpg.html?filters%5Buser%5D=125630029&filters%5Brecent%5D=1&sort=1&o=0&_suid=146531988388208623286652343182
The oil pan does need to be modified. All 4200's are front sump. Some have used a Colorado 3.5 pan and modified, others have done a complete custom pan, it's up to you.
http://s1074.photobucket.com/user/whitedog76/media/0412151150_zpsvckmdjkk.jpg.html?filters[user]=125630029&filters[recent]=1&sort=1&o=10#/user/whitedog76/media/0412151150_zpsvckmdjkk.jpg.html?filters%5Buser%5D=125630029&filters%5Brecent%5D=1&sort=1&o=10&_suid=146532011365705772995235663668
