Seeking advice from the GURUs..... I am playing with a GMC 302...... still getting acquainted to the engine...... this civilian motor came from a large grain truck from the West circa 1959..... it is a replacement motor factory clearly stamped 302 BUT no serial number......block has raised cast numbers...from memory 2324004 which indicates a 1958 to 62 run......

My 2403 looks very similar to the spare 235/261 dizzy....same cap same rotor...... BUT no vacuum advance. I will strip it down for in depth cleaning........ why do I need to install a vacuum advance??????.... will be used in a restored 4x4 with 4 speed synchro. Am I right in assuming that this 2403 would/possibly be different inside..... weight/springs calibrated for the 302 and a similar 261 dizzy with the vacuum advance would be slightly different although it fits the block????....... assuming that this is why Delco had so many models that had been tricked for specific engines....... or was it a marketing ploy????

Thanks for the education!!!!!

Last edited by Phak1; 03/16/2025 6:45 PM. Reason: Moved to start new thread
Bob C.
CMP Heaven
The Hammond Barn