Spark plug heat range question

[alamantia]

I dont know if anyone saw some of my recent posts but I just picked up a boat with a chevy 350 and a q-jet. Since we are blessed with this nice weather I procceded to start cleaning and fixing it up yesterday. When my father worked for pontiac I had an IROC and he gave me a bunch of tune-up parts. I still have 3 boxes of the old rapidfire spark plugs, when I say old, these things are from 1995 and they have that copper "star" electrode. I pulled the plugs from the engine yesterday, they looked ok but they say R43TS on them. The rapidfires I have are #2 which is the replacement for the R45TS

The R43TS is a fairly cold plug, the R45TS is are two heat ranges hotter. So today I was going to go buy set of R43TS because I want to put the propper plug in the engine, but I began to think, how different is it really? I honestly do not know myself. I suppose boat motors want a colder plug because they run at a constant RPM more than a car engine would and they are less suseptable to carbon buildup. Is that the only reason, or will running a hotter plug really detonate my engine? Does anyone know for sure?

[LTb1ow]

Can't say for 100% that it will cause negative things to happen, but that was a common thing to come across for spring tune ups, customers throwing in the wrong plugs, either a few steps cold or hot and the engine running like a dog.

[alamantia]

Your prolly right, F'n autozone didnt have any R43's so I just put the 45's in, im sure it ull be fine.