There's a gentleman who want to change his 1937 Oldsmobile straight eight's standard 3 speed transmission to a 1951-1953 Oldsmobile Dual Range Hydra-Maitc transmission, Will a 1940 to 1948 Oldsmobile straight eight Hydra-Matic bell housing and flywheel interchange ?
is the leak a small or weeping one ?, you might the GM approved radiator sealant that made from ground up ginger roots, the stuff works great, I hope you're running the original style pressure cap, 4 lbs ?
the contacts inside your turn signal switch and lever assembly may be worn out enough to have created trails inside that causes both dash indicator lights to light up together, I believe the same setup was used from 1949 to 1952.
you can not use a straight eight balancer on a straight six, the correct Harmonic balancer is # 511498, 1937- 1954 Pontiac six without power steering.
Charles L. Coker
1953 & 1954 Pontiac
Technical Advisor
Pontiac Oakland Club International