spark plugs

Reply Subscribe

Thread Tools

Search this Thread

02-21-2009 | 06:16 AM

eby94

Guest

Posts: n/a

spark plugs

I am in the process of working on a 1973 440 with 400/440 motorhome heads, I am having trouble finding spark plugs for this engine. I have already tried Champion RJ12YC and Autolite AP85 with no luck. The threads are good on the heads. I have heard that these heads take different spark plugs. PLEASE HELP

Reply Like

02-21-2009 | 07:37 PM

Commando

Mopar Lover

Joined: Nov 2007

Posts: 935

Likes: 0

From: New Jersey

What is the reach on the head for the plug, is it 3/8 or 3/4? I had Accel 437s for the stock 440 heads, but needed the 417s for the Edelbrock heads I got as they needed a longer reach.

Reply Like

02-22-2009 | 12:04 AM

66sportfury

Guest

Posts: n/a

autolite ap85s should be the plug.....autolites rock!

ill do some digging and see wat up. i didnt know heavy equip or industry heads were diff just knew the timing gears were.

Reply Like

02-22-2009 | 12:08 AM

66sportfury

Guest

Posts: n/a

but i need to know the year and make of the motor home

Reply Like

02-22-2009 | 06:41 AM

eby94

Guest

Posts: n/a

The casting numbers for the block show it be a 1973 440 block. The casting numbers for the heads show them to be 400/440 heads for 1973. This motor is setup for twin turbos going in a 1941 Plymouth.

Reply Like