So I want to know what the oem spark plugs for my 87 irocz 305 Tpi 5.0 manual. Can anyone answer this.

Also what is the gap for the 305 Tpi?

Someone please help

 

Acdelco copper plugs = OEM spark plugs? I know its Acdelco. Just don't know which model...

 

this one is really simple

R43TS

and if you want extended tip then get TSX suffix
X = extneded tip

and i get them for all my engines it makes for easier starts puts the spark farther into the combustion chambers, so much better

 

Thanks Randy! Those were actually the copper ones I was refering to. So you use the extended ones? You wouldn't happen to know the proper gap for the plugs for a 305 Tpi would you?

 

Not the X; that's "X"tra long threads.

R = resistor

The #s are the heat range; lower = shorter heat transfer path from nose to shell therefore cooler

T = tapered seat

S = extended nose

Proper gap = yes but not too much (.035" - .060", they come out of the box at about .045" if unmolested whihc is fine)

R43TS will work. Up to R45TS might be appropriate depending on usage and whatnot.

This isn't necessarily a "look it up in the book and it's perfect" kind of deal; fuel has changed since then, as have user expectations, speed limits, and alot of other stuff, up to and including the construction of the plugs themselves. Consider the "OEM" # as a good guide to a starting point for your tuning efforts.

Higher heat ranges tend to be better in lower compression engines, ones with really low rear gears, ones that burn oil, and ones that sit around and idle alot. Higher for ones that run at high RPMS alot either because they spend most of their time on the highway or racing; or higher compression such that there's risk of detonation.

 

Thanks for the info. So I had them changed to R43TS. I guess one plug was stripped out so they had to do kind of a tap they said I guess. Had them all changed for 130$ labor plus 20$ for new plugs. My dad said I made out pretty good. He said tapping it is a pain in the butt. Runs so much better got my timing all keyed in new plugs wires new cap and rotor. Im very happy with how she's running best she's ran since I got her like 4 months ago. Got the alignment done new tires new fluids and filters. Happy to finally see some results in how its running