My 292 / mumert intake / 500 cfm eddy / pertronix / isky cam / original manual 4 speed and 3.0 rear gears...
My question is that the engine builder used autolite 46 plugs. These are mentioned to be too hot on the y-block tune up page. I bought some 45s today and about to put them in. What other tuning should I look at when changing to a colder plug. Is there a better colder plug for my setup that the autolite 45s? 

46 interchanges with the stock heat range and for typically modified engines, it should work.

Depending on the cam and compression, the 45s might be better to try.  You shouldn't have to change the tune.

Plugs are personal preference.  Use a brand you trust and it will be fine.


Lawrenceville, GA