trying not to sound dumb but not succeeding what motor exactly are these plugs for?

 

go to sparkplug.com and search for TR6 application.. it will show you every vehicle

 

thanks, wasn't sure being that the heads are different. but if tr6's work so be it. we are at about 5 psi now but the plug wires are burnt i think so we have to replace them.

i found my confusion. the older style heads used ur6's. but the vortecs i guess got a different plug holes lol.

 

wat about the tr9s i heard there colder