Pontiac - Race The next Level

          
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Old 10-23-2019, 08:21 PM
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Default 421 S/D bob weight?

Would any of you gentlemen know what the factory bobweight of a 421 S/D was or the individual piston, pin connecting rod weights were?

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1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph
1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car.
1980 Formula 350 Pontiac back burner project
1972 LeMans 350 Pontiac
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Old 10-24-2019, 06:20 AM
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I have a few SD Rods with Mickey Tompson Pistons still hung on them, I can try to check those for you if you want , but why do you need to know?

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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

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Old 10-24-2019, 09:16 AM
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Quote:
Originally Posted by steve25 View Post
I have a few SD Rods with Mickey Tompson Pistons still hung on them, I can try to check those for you if you want , but why do you need to know?
Thanks Steve, I'd really appreciate it if it's not a inconvenience for you. That's a fair question, I have a 990 crank that I am about to use in a 428 build. I have a current bob weight of 1554 grams (w/o bearings) so was curious on what kind of weight changes (plus or minus) I could expect on my crank.

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Johnny US Army Retired
1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph
1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car.
1980 Formula 350 Pontiac back burner project
1972 LeMans 350 Pontiac
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Old 10-25-2019, 06:09 AM
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I will post up what I find out tomorrow morning.

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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #5  
Old 10-25-2019, 11:27 AM
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Quote:
Originally Posted by steve25 View Post
I will post up what I find out tomorrow morning.
Thank you Steve!! Can I bribe you to post a picture of one?

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Johnny US Army Retired
1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph
1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car.
1980 Formula 350 Pontiac back burner project
1972 LeMans 350 Pontiac
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Old 10-28-2019, 07:05 AM
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Sorry for the delay, but here's the info.
The total for the rod, pin , piston, rings and Bearings is 1723.66 grams.
The piston on this rod is a L2189 .030", so it's not a original one as I thought.
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__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!

Last edited by steve25; 10-28-2019 at 07:52 AM.
The Following User Says Thank You to steve25 For This Useful Post:
  #7  
Old 10-28-2019, 10:04 AM
tom s tom s is online now
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There were 2 diff pistons used in the 421 SD program.M/Ts and Forgedtrue.Tom

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Old 10-28-2019, 11:53 AM
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Thank you for sharing that Steve, cool stuff!!

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Johnny US Army Retired
1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph
1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car.
1980 Formula 350 Pontiac back burner project
1972 LeMans 350 Pontiac
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