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| | | | Joined: Nov 2007 Posts: 29 'Bolter | | 'Bolter Joined: Nov 2007 Posts: 29 | The truck came with autolite 295. Is there a hotter plug ? or longer that goes in cyl. without hitting the piston? Is there a resister plug? thanks for your help 7m | | | | | Joined: Feb 2004 Posts: 29,807 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,807 | I think the original equipment plug was an AC #45. A slightly hotter plug would be a #46. Colder, 43 or 44. The 43, 44, and 46 are not being produced now, so 45 is the only AC number currently available at most FLAPS. Don't substitute a 45T or 45TS- - - -they're tapered-seat plugs for later model engines, and they don't have a ring gasket.
Champion and Autolite have plugs that cross-reference to the AC numbers, so it might be necessary to switch brands. Original-equipment AC's still show up on Ebay occasionally. If you can find a set ot C-45 plugs, they're the commercial type that were used for delivery trucks, taxicabs, etc. The electrodes were bigger, and those plugs would last a lot longer. I used to run C-43's in the dirt track car with a warmed-up 327, and I could clean and re-gap them several times before replacing them. Regular plugs only made it one or two nights of racing before needing replacement.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | I would use an AC R44S or R45S. That is a more modern plug replacement for the original 45. The extended tip works great in O-head valve engines. It resists fouling & runs cooler. The resister reduces radio interference if you have a radio & other comunications that you are driving close to.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Nov 2007 Posts: 29 'Bolter | | 'Bolter Joined: Nov 2007 Posts: 29 | Thanks you for your help. I stop at NAPA and pick up ACDELCO R46SZ . We look at a lot of plugs ended up with R46SZ. Hotter then the stock ones and resister. There are a little long .070 and clear the piston. Thanks again 7M | | | | | Joined: Sep 2010 Posts: 222 Shop Shark | | Shop Shark Joined: Sep 2010 Posts: 222 | 7M
Can you let us know how the R46SZ plugs work for you and your 261?
Cheers,
Nick
| | | | | Joined: Sep 2010 Posts: 222 Shop Shark | | Shop Shark Joined: Sep 2010 Posts: 222 | Hey 7M
So how are they working out for ya?
Cheers,
Nick
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