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Discussion Starter #1
I like Autolite plugs, what would be a good number for a 468 BBC ,tunnel ram, dual 750s, vertex mag,Basset headers, fairly low comp, maybe 10 to 1 at most. It's a v-drive with two blade prop, dont know the pitch or what gears are in the v-drive It's in a 73 Hondo flatbottom. Any suggestions?:)Unsure
 

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Some guy
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You didn't say what heads are on the engine, so there is no way of knowing what plug you need, since early or late BBC iron heads use different plugs, as would aftermarket aluminum heads.
 

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Discussion Starter #3
You didn't say what heads are on the engine, so there is no way of knowing what plug you need, since early or late BBC iron heads use different plugs, as would aftermarket aluminum heads.
If I remember right , the casting # is 049 . They are oval port open chamber.
 

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I ran Autolites for years. Figured if they could fire a Ferd, they had to be pretty good :p Like Barry said, gotta know what head you're using to suggest a plug.
Recently, I've since switched to NGK since that's what my dyno guy is used to and you can get them for about $1.60 each when you buy them in quantitys :)devil Helps a bit since my crew doesn't seem to understand you actually CAN put a used plug back in a motor.... :D
 

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Discussion Starter #6
OK then, what NGK plug? I am always willing to take good advice. Casting # on heads are 049, open chamber oval port. Also what gap do you suggest?
 

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Here is the thing with auto light.... Let’s just say it’s a Chevy 350. Autolite will make 2 plugs to cover 4 heat ranges. My belief and my engine builder who builds my race engines for my Grand-am Rolex car (Roush-Yates) their is no way that 1 plug can cover 2 heat ranges. Also if you compare a NGK and an Autolite on a scope and look at the KV patterns the pattern of the autolite plugs is very poor. Almost as bad as a Bosch Platinum plug which I say is the worst plug you can buy.

 

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OK then, what NGK plug? I am always willing to take good advice. Casting # on heads are 049, open chamber oval port. Also what gap do you suggest?
NGK V-Power...P/N: YR5....040 gap

NGK GP Platinum...P/N: YR5GP....040 gap

these are 2 good plugs...the GP Platinum might be a better choice for ur app (c.i., ign, etc)...they last alot longer :)

just my .02 cents :)

FastRat
 

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NGK part#5155 That is an NGK fr4. Since you are running a mag you need to gap them .020 - .025
The FR4's are a long reach gasketed plug, the 049 heads should take a short reach tapered seat plug like a UR4 or 5. Another thing to keep in mind is with ngk the lower the number the hotter the plug opposite of autolite. If you still wanted to run autolites you would be looking at a 24 or 25.
 
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