The park brake normally goes on the last transmission, so since it is on the main trans., it might be true that the 'Brownie' was added later, whatever, must always make sure the 'Brownie' is in gear when using the park brake. If the park brake is a ventilated disc, that is a Tru-stop brake, shoes can be relined if needed, there is a place here in Denver, CO that does that if cannot find local place. If the brake is a cast drum, the linings are on curved shoes, local brake/clutch place can relined if needed.

302 is a good engine, parts are available.

Does it run now?

It probably does not have 'spring brakes' now which is OK, however, adding them to the rear would be good, especially if the park brake is Inop. If there is no air park brake, knob one pushes or moves before able to move truck, then no 'spring brake'.

Ed

Last edited by EdPruss; 03/29/2017 2:14 PM.
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.