440 heads do not accept Autolite 85's

[vintagetin]

Autolite 85's will not fit in my 440 heads. The block has the casting 1975 on it. Not too familiar with the variety's of heads. The shank on the 85's and Champion 14's are too big. There is a small notch on the heads that keep the plugs from getting threaded.

Also, the valve cover says it was a BUS or MOTORHOME engine. Funny thing is, according to this site:
http://www.440source.com/dampers.htm

Buses and motorhomes should have the internally balanced cranks shaft with the offset bolt pattern harmonic balancer....
My engine does NOT have the harmonic balancer. It has the #3577785 harmonic balancer for externally balanced cranks on it. I have yet to start it...so I guess we'll just wait and see if it vibrates real real bad.

 

[67 B-body]

Is it a cast or forged crankshaft?

 

[vintagetin]

being a 75 should be a cast

 

[67 B-body]

then you'll have a external balanced balancer....

 

[vintagetin]

Sweet. Any ideas on proper spark plugs?

 

[Cranky]

Some years of motor homes used the smaller thread spark plugs....

 

[vintagetin]

Some years of motor homes used the smaller thread spark plugs....

I was hoping someone would say that! Now I just have to see if I can't find a part #.

 

[IQ52]

I was hoping someone would say that! Now I just have to see if I can't find a part #.

It takes about 15 seconds to find this out online. Bosch 7969, a buck 50 cents each from Summit racing.

 

[vintagetin]

I used autolite 24's. Looked it up in the autolite paper catalog at O'Reilly. Only used in RV's and Buses. Still hoping is an externally balanced steel crank rather than have the wrong harmonic balancer on it.

 

[Al K]

Are you running headers? If so,you may want to consider Accel 437s plugs. Only about 2-1/2 inches long. I run those to keep the plug wire boots off of the pipes.