1985 GMC w/350, 700R4, NP208 transfer case?

Question

the 350 in my truck was just recently rebuilt, 0.30 over pistons, .20 under crank, .488 lift comp cams cam, lifters and springs. The problem is that sometimes there is a noise that comes from inside the engine, sounds like something is rattling against one of the counterweights on the crankshaft, took the oil pan off and found the oil pump pickup laying on the bottom of the oil pan, so I put the pickup back on and then tack welded like it was suppose to be. But the rattle is still there, not all the time, just when it's cold or I turn a corner really fast. I can sometimes hear it when I crawl under the hood and rev the engine really hard. Could something be broke in the transmission making that sound or could it be my flywheel doing it. Already ruled out dipstick, checked the torque converter bolts, and the bellhousing bolts. Although the bellhousing bolts were a little loose.

Answer 1

if the pickup tube fell off and you started or drove the motor with it off then you could have hurt the motor. you have more or less run it without oil, or oil pressure for a temporary time. you may have scalded a bearing. you may have also hurt a lifter it may have drooped the pressure enough to collapse the inside of it. this would be the easier fix but the hardest to find out. you may need to pull the intake, valve covers, rocker arms, and the lifters to see if this has happened

Answer 2

Cam bearings.
The most forward, or furthest one back.

I had the same truck, short bed k-10.
The bearing set had all the same size bearings.
But, one bearing journal, the most forward, was just a little tiny bit bigger and the bearing fit too loosely and rattled out of place while the engine was running.
Had less than 20 hours on it.

For your sake, i hope it's not the same problem.

Answer 3

there is extra to this than the others have pronounced. with the intention to bypass to a 2wd truck you will would desire to do certainly one of two issues different than basically removing the pass case. you will the two would desire to interchange the transmission with a 2wd form or replace the transmission output shaft with the 2wd version and set up the tail housing. changing the output shaft will require disassembling approximately 0.5 of the transmission. Swapping stuff in automobiles is seldom so uncomplicated as curiously from the exterior.