Metric 200 - What do I need to make one last

Bob Don · 06-01-2020, 05:24 PM

Get a J.W. Performance Ultra Bell. I cracked two cases before getting one. The case is the weak link on a TH200

https://racewithjw.com/product/ultra...-metric-to-gm/

Mark Yacavone · 06-01-2020, 06:18 PM

If you don't go with the 350/400 changeover option, you still want to get a hardened stator support shaft insert.

B Parker · 06-01-2020, 08:26 PM

Real simple Sepanek Racing Transmissions. I have 75 runs on his metric in a Big Block Chevy stocker. It's a 1970 402/375 hp making 635 hp. It's the fastest trany I've had in my car and it has lasted. BP

Lee Valentine · 06-02-2020, 05:21 AM

Sepanek all the way,best and fastest out there

KennyAnderson · 06-02-2020, 07:32 AM

Thanks guys and keep em coming! I've been told the Metric 200 is about a tenth faster than a TH350. Hoping this is true??? I would hate to leave that on the table but I'm wrestling with the durability of the 350.

GUMP · 06-02-2020, 08:20 AM

A good one will be fine behind an LT1. It will also be a little faster.

Alan Nyhus · 06-02-2020, 08:35 AM

Billy Lynn does also a great Metric 200. If you've got a TH350/400 convertor, you can have a input for those installed along with the appropriate pump mods. The governor driven auto 1-2 makes them very consistent. The JW bell housings are a worthwhile addition or you can fabricate a brace for the stock case. Also, the Lokar flexible dipstick makes life a lot easier. The marks on the Lokar unit aren't correct so you need to remark it relative to the oil pan flange on the case. Retapping the oil pan holes to 1/4X20 from the metric size is another thing to do to simplify things. If you elect to have a roller rear bearing installed in place of the bronze one, the drive shaft yoke will likely need to be turned down about .020 for proper fit.

For what it's worth. -Al

Billy Lynn (501) 278-0651

nhramnl · 06-02-2020, 09:19 AM

I recently had the rear end of my car apart to change the ring and pinion, and when I was re-installing the driveshaft, I noticed that the output shaft of the McClay THM200 in the car seemed to be free to move around an awful lot. I immediately checked my spare McClay THM200, and the output shaft was exactly the same. With the driveshaft installed, the movement was all but gone. Never noticed that degree of movement with Powerglides or THM350s. Does the driveshaft slip yoke stabilize the output shaft that much, in a THM200?

Jack Matyas · 06-02-2020, 01:45 PM

I've had units from both Turbo Action and Jack Sepanek and both companies will build you one that will last and get you into the winners circle .

Mark Yacavone · 06-02-2020, 06:29 PM

All good options, so far ..
At least one missing... Think West...Way West ;-)

06-01-2020, 05:24 PM	#1
Bob Don VIP Member Join Date: Oct 2002 Location: Greater Boston Posts: 1,497 Likes: 1,135 Liked 905 Times in 193 Posts	Re: Metric 200 - What do I need to make one last Get a J.W. Performance Ultra Bell. I cracked two cases before getting one. The case is the weak link on a TH200 https://racewithjw.com/product/ultra...-metric-to-gm/ __________________ Bob Don 128 SS

06-01-2020, 06:18 PM	#2
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,821 Likes: 2,912 Liked 5,133 Times in 1,957 Posts	Re: Metric 200 - What do I need to make one last If you don't go with the 350/400 changeover option, you still want to get a hardened stator support shaft insert. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

06-01-2020, 08:26 PM	#3
B Parker Senior Member Join Date: Sep 2009 Posts: 851 Likes: 981 Liked 2,343 Times in 465 Posts	Re: Metric 200 - What do I need to make one last Real simple Sepanek Racing Transmissions. I have 75 runs on his metric in a Big Block Chevy stocker. It's a 1970 402/375 hp making 635 hp. It's the fastest trany I've had in my car and it has lasted. BP

06-02-2020, 05:21 AM	#4
Lee Valentine Senior Member Join Date: May 2004 Location: Brookfield, CT Posts: 708 Likes: 13 Liked 319 Times in 68 Posts	Re: Metric 200 - What do I need to make one last Sepanek all the way,best and fastest out there __________________ Lee Valentine 1661 STK

06-02-2020, 07:32 AM	#5
KennyAnderson Member Join Date: Sep 2013 Posts: 290 Likes: 38 Liked 357 Times in 119 Posts	Re: Metric 200 - What do I need to make one last Thanks guys and keep em coming! I've been told the Metric 200 is about a tenth faster than a TH350. Hoping this is true??? I would hate to leave that on the table but I'm wrestling with the durability of the 350.

06-02-2020, 08:20 AM	#6
GUMP VIP Member Join Date: May 2002 Location: Shelby, NC Posts: 1,824 Likes: 2,174 Liked 2,355 Times in 554 Posts	Re: Metric 200 - What do I need to make one last A good one will be fine behind an LT1. It will also be a little faster.

06-02-2020, 08:35 AM	#7
Alan Nyhus VIP Member Join Date: Dec 2002 Location: Lower Dakota territory Posts: 1,180 Likes: 1,074 Liked 799 Times in 236 Posts	Re: Metric 200 - What do I need to make one last Billy Lynn does also a great Metric 200. If you've got a TH350/400 convertor, you can have a input for those installed along with the appropriate pump mods. The governor driven auto 1-2 makes them very consistent. The JW bell housings are a worthwhile addition or you can fabricate a brace for the stock case. Also, the Lokar flexible dipstick makes life a lot easier. The marks on the Lokar unit aren't correct so you need to remark it relative to the oil pan flange on the case. Retapping the oil pan holes to 1/4X20 from the metric size is another thing to do to simplify things. If you elect to have a roller rear bearing installed in place of the bronze one, the drive shaft yoke will likely need to be turned down about .020 for proper fit. For what it's worth. -Al Billy Lynn (501) 278-0651 __________________ "That'll never work....."

06-02-2020, 09:19 AM	#8
nhramnl Senior Member Join Date: Feb 2010 Posts: 507 Likes: 8 Liked 358 Times in 83 Posts	Re: Metric 200 - What do I need to make one last I recently had the rear end of my car apart to change the ring and pinion, and when I was re-installing the driveshaft, I noticed that the output shaft of the McClay THM200 in the car seemed to be free to move around an awful lot. I immediately checked my spare McClay THM200, and the output shaft was exactly the same. With the driveshaft installed, the movement was all but gone. Never noticed that degree of movement with Powerglides or THM350s. Does the driveshaft slip yoke stabilize the output shaft that much, in a THM200?

06-02-2020, 01:45 PM	#9
Jack Matyas Live Reporter Join Date: Nov 2001 Location: Bethlehem , PA -Christmas City , USA Posts: 4,932 Likes: 410 Liked 2,052 Times in 400 Posts	Re: Metric 200 - What do I need to make one last I've had units from both Turbo Action and Jack Sepanek and both companies will build you one that will last and get you into the winners circle . __________________ Jack Matyas 1547 FS/C 2015 Camaro COPO # 62- 2012 Camaro Convertible COPO

06-02-2020, 06:29 PM	#10
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,821 Likes: 2,912 Liked 5,133 Times in 1,957 Posts	Re: Metric 200 - What do I need to make one last All good options, so far .. At least one missing... Think West...Way West ;-) __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

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