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What type of plugs and what size gap for 97 gtp grand prix has 2.8 pulley gonna put a 3. Cam,header, injectors, fuel pump, exhaust.
 

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Coldest available. 2.8 pulley is a lot of boost and heat to deal with. I use double platinum autolites. Coldest range. I have a set of Tr7 iridium I will use later.
 

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Alright thanks man any idea what size I should gap them. Zzp had a reference but they deleted it I think was like a chart if what mods needed what size gap
 

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You will need larger fuel injectors too. 42.5 lbs, and you will need a custom tune. Contact Dyno Brian on this forum. He has helped a lot of 3800 members.

With your setup, I would consider .050. I do not like dealing with misfires...:icon_surp
 

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ive got bigger injectors just not sure what size previous owner did them so ill figure that out this weekend so double platinum autolites with a .50 gap
awesome thank you.

would this same set up hold true if i were to go up to 3.0 pulley
 

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Yes. The worst you can do with too cold plug is fowl it.

There is controversy about the best cold plug. My choice with Autolite Double Platinum is one of preference.
 

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I also run autolites in mine with a 2.6 and MANY mods. Never had any issues with these plugs at all (but copper core is probably best for maximum preformance because they do shed heat faster). But for a street driver the double plats work flawlessly.

Many many tears ago when growing up on the west coast, I was fortunate enough to get acquainted with some of the good old boys of hot rodding (Fred Hayes, Ollie Morrison, Micky Thompson, Ray Allie, etc). It was a pretty unanimus thought on their part that spark plug application(except for heat ranges) was determined by combustion chamber shape/design). SO, for this reason I've always stuck with the oe plug gap. My take on this issue is the chamber size and shape dictate what air fuel flow will be into the cyl and the engineers determination of how to light the fuel via plug spark is pretty important. Under hard use a colder plug of the same design gives better preformance......... too much info........ Jake
 

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The Pic of my 68 Firbird had a bored out 421S.D. AC plugs, and Champion plugs
fouled on my engine. I do not think they were very well designed. I tried Autolites, and never found a better plug. Granted, I had about 13 to1 compression , but I had one of the first Mallory Unilite Infrared igniton with Electronic coil. Very hot ignitin..made all the difference. Hey Jake= I ran a rare Mickey THompson Cross Ram intake...cheers
 

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Did you say a "cross-ram" intake manifold! I remember when those first showed up on the 413/426 chrys engines way back in the days. I also remember running one of those on an old-school 301 small block(this was before the 302 came out with GM. Nowdays there are some really nice intakes out there. I personally like the BRODIX stuff. excellent designs and work very nice. And of coarse there are some very good carb options also. On my last couple of race engines (355 and 434 small blocks) I had Chuck Newton hollys that were VERY good (and dyno proven to give more power).
 

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Those are 660 holley center squirters with blower scoops on the pic. Mickey Thompson cross-ram... pretty rare I would guess...
The old guy I bought the engine from was a real race nut. That was back around 1975 or 76.
He had another engine he called a 389 Daytona. He had a custom oil pan with
a number of cooling tubes running through the pan.
I ran 455S.D. rods and the 421S.D. had a forged steel crank and 4 bolt mains.
I ticked off a lot of fast motorcycles too...cheers
 
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