LuckyPenny
Petty Officer 1st Class
- Joined
- Feb 21, 2003
- Messages
- 256
I know reference material is as hard to get as parts of older engines, but I have a short question. I have a 1977 Mercruiser 250 (350 CID (5.7L)) and would like to know what the proper spark plugs are. Currently it has R43T's installed. What reference I can find lists that plug for the 1990's version.<br /><br />What is the correct plug? also temp range (hot, midrange, cold)