440 motor home engine,spark plug ?

I bought a freshly rebuilt 440 engine that came out of a 78 Winnabego motor home. I installed it today in the Chargervert,while I rebuild the 440 that came out of the car. I bought a set of spark plugs for a 70 440 and the don't fit. Did the later 440s take a different plug? If so does anybody have a plug number,so I can get plugs that fit? Any info would be a great help. Thanks Pete.

Yep, some motorhomes took a different plug even with the 452 head casting...No compression washer and possibly a different size{smaller} IIRC...Could'nt NAPA{or local auto parts} cross it over for you ???

i had the same problem, the motor home 440 have a different head, you have to use different plugs, i have 1973 motor home 440, i have to use autolite AP 26 or A/C Delco R44TS, you may can cross reference these numbers and get the brand of plug you want to run

yep,it would be the small 5/8" hex,tapperd seat (peanut plug)

i run autolight 23 in my 78 440 MH engine

Thanks guys,I bought a set of Autolite 85 plugs,but I have ten other cars I can use them in,so they won't go to waste. The smaller peanut plugs will actually be a blessing,as the larger plugs are really tight fitting with the headders I have.