I don't mean to sidetrack the response by Kevin. The 1952 GMC did not have turn signals. Dealerships and owners added them. The upgrade that your uncle made was historically correct for that era. Today no one wants to stick their arm out the window and signal for a left or right turn. The generation of today may interpret that as an obscene gesture and might lead to road rage or worse.

The 1154 bulb is larger and I believe the new reproduction housings have the socket inside mounted on an angle so that it doesn't interfere with the lens. Needless to say this upgrade is not stock either but appearance is close to original.

"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."