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Back in the ol days we ran a 10.2 block with a 4.8750 stroke from Fulton. 4.84 space. Donovan was the go to then. We ended up at 11.2 deck .600 raised cam. one of the best combos I liked was a 738"
 

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Look at it like this. If you take the stroke out of the deck height it gives you this
10.4"-2.5"=7.9"
10.2"-2.375=7.825"
10.2"-2.25"=7.95"
If you take remaining height for rod and piston and decide by stroke it gives you a ratio
7.9" height ÷ 5"stroke=3.16
7.825" ÷ 4.75"=3.29
7.95"÷4.5"=3.5

Stroke eats deck height up pretty quick
 

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T/S 368E
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4.600 x 4.75 in a 10.4 block will make excellent power with a 9-12* head & nice reliable rotating assembly!!!
At least that was something I was considering until I decided to go insane wanting 6.90's N/A combination.

I don't see how you could make less than 1200 HP even if you tried??

For the record, my last combo ran 7.60 at 2600 lbs with 1100+ HP, so with that weight, he will be all set.


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For the record, my last combo ran 7.60 at 2600 lbs with 1100+ HP, so with that weight, he will be all set.
That's what I think too! So is the car certified to run faster then 7.50? Because a basic 632 pumpgas conventional head motor with some thought would get him there @ 2450 and 7.50 ET's. Guys on here with 3200lbs streetcars are running 8.50 with way less power. Had a nice chatt with Darin Morgan on a PG 632 as I was look at a set of his designed heads. He said the cam/intake/heads is the key obviously and they have been though a ton of combo's at RM. NOTHING to get a 632 past 1000Hp on pumpgas.

If the car is chassis limited, I would go pump gas 11.+ DH 5.0 stroke Sniper XL or HH heads, nice cast single and Holley Sniper 4500 EFI for bracket. Bob has seen fast cars (1300+Hp) with the Sniper and very consistent too. Big inch doesn't need to worked as hard for longevity.
 

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He is thinking big inch for easy hp. Car is 7.5 certified.
Are you building it or just helping? That good size budget will help. Think Nyes or Andy Beal will get you a nice piece that would do what you want and still have "pizza money" left over.
 

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Discussion Starter #29
I'm not building it. I am just looking for ideas for him before he starts calling builders.
 

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If your going that cubic inch area,dont waste your time on 4.840 platform.Go right to 5.0" and have something worth while when done.4.750 bore x 4.750 stroke is a great combo.Put it in 10.700 deck block and help rod ratio.This is 2020 dont build that old dinosaur 4.840 tech.Dont build this size engine and be stuck with 2.350 or 2.400 valves.2.520" is min I would want at 650 inch.
 

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There are different factors to consider,but with only a 1200hp goal,you really don't have to go crazy.raised cam 10.200 iron block,55mm cam tunnel,x pattern,maybe .937 lifters.11x or 12deg or even sr20s will get u there with a single carb.my buddy just did a 598 with 1203s that made 1220 with a single carb.
Yes 582 to 598 with conv head.You will have way better valve trane geo and longevity. Several guys around country run 7.50 with these combos.Several run 7.20s etc.
 

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We do our own so I dont know.I didn't have 25k in last one we did.Basic parts all pretty much same price area is what we find.If you only wana go 7.50 you dont need to spend 25k and you dont need anything other than std conventional bbc components.And you sure wont do any quick 16 racing on 25k budget unless your track only has 15 cars.
 

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Viper is right, you could look into 5.0 BS stuff, but not needed. Most REAL 1200Hp motors will run WAY past 7.50s. So look into about 1075Hp motors. That will get you your 7.50.

Plenty of used 4.84 BS motors out there, fresh and will meet your goals. You could look for a used BES 525 or Texas ProStock engine and maybe detune them sum. If it were me, I would look for the heads/intake and buy the best you can, and work back from there.
 

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5.0 stuff would be sweet and make the power with one rod tied behinds it's back.
As mentioned, way over kill for a car that's not legal for it.

Just about any big chief will make 1200 HP, even if you buy a N2O combo & pull it off.
Like I also said, there is a ton of conventional stuff making 1100 HP, so this should be an easy goal.

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Discussion Starter #36
So it looks like the 4.600 x 4.75 in a 10.4 block has the best pin height of 1.225 with a 6.8 rod. Am I doing this correct?
 

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Call Nyes and ask for Pat. Fair prices and well researched combos. Their bracket race 632 makes 1075 with mild cam for $15K. My friend has one and it is a nice piece. HH conventional heads. Standard Dart 4.600" iron block, 4.84" spacing and 10.2" deck.
 

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NO, you match the rod to the pin height you prefer.
My 582's all used a custom rod to get the best ratio.
Some heads you may have to do custom both, one of mine had rolled over heads, so everything was custom.

Don't remember which cost more, custom rod or custom piston, I trusted my guy to do the math, I just write the check.

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