Update on plugs. I got a set of AC- R45S from NAPA. Only cost about $1.70 each.
What a difference !! Starts and runs so much better. Vacuum gauge holds steady in the green at 20".
The old ones looked wet and fouled. They were R 43 without the extended tip.

57 GMC LCF 370
55 John Deere 40-W
59 John Deere 430-W
2000 GMC 4x4
56 John Deere 420-W
Pix on Photobucket