PROJECT "LAID BACK" - 1978 CENTURY 2 DOOR AEROBACK

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MrSony

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Nov 15, 2014
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Des Moines, Iowa
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MrSony

Geezer
Nov 15, 2014
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Des Moines, Iowa
I'll take a 12 pack of coke.

Anywho, I would call up Hughes and see what they can do about a 2500 BOP TH350c converter. I don't see one listed on the site. If they cant help, I'd just go with a standard Th350 for the time being, less headache in the converter department. On summit anyway, all the TH350c converters I see are for a Chevy. I'm sure they could work, and idk about 455 flexplates, but all my 350 flexplates have multiple bolt holes (bout 9 in total) for the converter.

And I used the street (orange I think, might be red, the instructions tell you what is what) spring in my trans, I can get it to chirp the 1-2 if I roll out at half throttle and mash it. Spins, catches, URRP then catches 2nd. With the "race/competition" spring, it might do it all the time. It's not hard to change out, just annoying. If you have lower numerically gears and tall tires it might not do it as much.
 
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JAMCAR223

Royal Smart Person
Jun 6, 2014
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1 as of tomorrow.
Well if that the case, you have experience well beyond your age. And HAPPY BIRTHDAY!! I assume that means your 20. My birthday is in 3 days (26th) but I'm old enough to be your Dad, LOL. I'll be 50 - Dammit! Luckily I do not feel that old. I tell you what.... I'll go to the car show today, and we can celebrate with win# 51 (I'm pretty confident, huh) with my GN. It's 2:30am, I better go clean the GN up, and get her ready.
 
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Texas82GP

Just-a-worm
Apr 3, 2015
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Spring, Texas
He really should be MrBuick instead of MrSony! Totally agree on going with Transgo. I have their shift kit in the 4L70E in my truck.
 
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MrSony

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Nov 15, 2014
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Des Moines, Iowa
He really should be MrBuick instead of MrSony! Totally agree on going with Transgo. I have their shift kit in the 4L70E in my truck.
I've been MrSony so long, might as well keep the name. MrBuick has a nice ring to it though.
 
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Oct 14, 2008
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Melville,Saskatchewan
Sure enough, I see the bolt issue you're talking about on the stock converter I have here. NOTED! That TransGo kit has 5 stars, so they must agree with you.
So option ( A ) TH350c - B&M rebuild kit ( or equivalent )
- TransGo 1&2 shift kit
- BOP specific 2500 stall for TH350c
I have no experience in rebuilding transmissions, but I have that covered, as my GN buddy is a transmission builder by trade.
Can someone in the Des Moines area buy MrSony a beer :):)
I contacted Hughes on that converter, it is a lug style converter. Their converter stall is also rated at 500 hp, so it stalls lower than some other brands of converters. They stall low 2's on SBO motors, would be closer with a 455. Yes, most prefer the Trans Go kit. I was going to buy both but can't get my TH350C to lock up. New solenoid and direct wiring did nothing, whole reason I went TH350C. The stock converters stalls at 1600 rpm, pretty sucky. The 75/76 455 block is supposedly stronger and the heads have bigger chambers and flow worse.
 
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JAMCAR223

Royal Smart Person
Jun 6, 2014
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I contacted Hughes on that converter, it is a lug style converter. Their converter stall is also rated at 500 hp, so it stalls lower than some other brands of converters. They stall low 2's on SBO motors, would be closer with a 455. Yes, most prefer the Trans Go kit. I was going to buy both but can't get my TH350C to lock up. New solenoid and direct wiring did nothing, whole reason I went TH350C. The stock converters stalls at 1600 rpm, pretty sucky. The 75/76 455 block is supposedly stronger and the heads have bigger chambers and flow worse.
Ok, so Hughes DOES have the correct converter for this application. I've read in the description of several converters that the stall speed is figured using a Big Block, and that Small Blocks will stall at a lower RPM. I should have a true 2500 stall speed with the 455. Jared, and yourself have 2 more votes for the TransGo kits, so that's a done deal, regardless of which transmission I go with.

I'm going to get a "regular" TH350 core as well for $60. I just got to go pick it up. So this same scenario would also work with that transmission, as well.

Well, I got the better ( high Nickel ) 1975 block, assuming everything checks out at the machine shop, but unfortunately got the shitty heads with it ( door stops ). Those will be replaced. Keep checking in olds307/403. I can use all the help/advice I can get from you guys.
 
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JAMCAR223

Royal Smart Person
Jun 6, 2014
1,853
5,507
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Houston, TX.
MrSony... Cheers to you, Sir. At 20, you can be called "Sir" now. There is no "teen" anymore :giggle:. I won Best GM today.

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Ok... Enough of the GN, back to the Century.
 
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MrSony

Geezer
Nov 15, 2014
6,828
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Des Moines, Iowa
Ok, so Hughes DOES have the correct converter for this application. I've read in the description of several converters that the stall speed is figured using a Big Block, and that Small Blocks will stall at a lower RPM. I should have a true 2500 stall speed with the 455. Jared, and yourself have 2 more votes for the TransGo kits, so that's a done deal, regardless of which transmission I go with.

I'm going to get a "regular" TH350 core as well for $60. I just got to go pick it up. So this same scenario would also work with that transmission, as well.

Well, I got the better ( high Nickel ) 1975 block, assuming everything checks out at the machine shop, but unfortunately got the shitty heads with it ( door stops ). Those will be replaced. Keep checking in olds307/403. I can use all the help/advice I can get from you guys.
All buick blocks were high nickle. That's why they didn't have hardened exhaust seats. The whole engine, heads and all, were technically hardened. Which is how they can use the "thin wall casting" and be lighter but retain the same strength as it's GM brethren.
I have the GM25BPO converter from Hughes, foot stalls to 2000, flashes to 2600. They're rated for BB (for some reason), so it should foot stall at 2500, may flash to 27-3000.
 
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