What T-case to match a th700r4 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

idastang · 03-15-2010, 11:16 PM

Hi, I am looking into changing my th350/203 for a th700r4. What I am not sure about is what year trans and t-case should I be looking for? This is for a 69 short bed with a 12 bolt rear and a dana 44 up front. The engine is a 327. My goal is to have something that will cruise the hyways a little better at lower rpms. I am runing 32s and not sure what the gearing is. Is there some way to id the gearing? I know the front dana 44 is from a 76 k5 blazer based on the BOM number. I not sure if I will be able to find a matched set together so I need to know what to look for in a th700r4 and t-case. Thanks for any help.

timcrow00 · 03-16-2010, 12:09 AM

mine is a 241 behind my 4l60e which is the same bolt pattern as your 700r4. but ive read they dont do well with tall tires so...

Hoods69BadBowTie · 03-16-2010, 12:20 AM

Yea 241s will bolt right up same as 208s is what I have heard.

munger · 03-16-2010, 10:48 PM

82-87 700r4s had the np208 transfer case you do not want a 82-87 700r4 they are notorius for failing unless you update them a little
87-91 suburbans had the np241c right hand drop same as 208 but only suburaban pickups has ifs and had the np241 left hand drop

USSkoval · 03-16-2010, 11:12 PM

208 is most common behind a 700r4, but to use the 208, you will need to use the associated shifter and mini console/boot setup. To get use out of the OD without bogging it down, you will want a 3.73 gear, maybe even a 4.10 ratio.

If you don't want to run the common 208 tcase, you can run a 205 from behind a th350. There is a spacer made for this that goes between the tranny and the adapter for the tcase.

AJs72K5 · 03-16-2010, 11:55 PM

The 241 is a direct bolt on to either a 700r4 or a 4l60e as mentioned. On straight axle trucks, 241s are passenger side drop. When GM went to IFS (independent front suspension), the 241s were driver side drop. I'm running one behind my 700.

The 241 has two weaknesses: the aluminum case and the slip yoke on the rear output. Both are easily corrected with 1) a good skidplate and 2) and JB Conversions Slip Yoke Eliminator (SYE). Otherwise, the 241 is a great case with a deeper low gear than a 205. There are guys on CK5 wheeling 241s with 42" tires and larger.

doug70 · 03-17-2010, 08:27 AM

There are some 241 pass side drops. I have one that I had planned to use, but I went to ford dana 60 solid axle for that truck so I stayed with the Bw4401. That Tcase is a monster but drivers drop only. 1970 cab and clip on a 97 Ford f350 frame, 427BB/nv4500, dana 60 rear too.

Doug

idastang · 03-19-2010, 01:03 PM

Wow, this is what I like about this sight. Lots of good info on simple questions. Thanks for all who replyed and if someone has something more to add, keep it coming. I am sure this info is of help to others as well

Beelzeburb · 03-20-2010, 10:21 PM

Small world, idastang is probably 10 minutes from my house.
I personally ran my original NP205 behind a 700R4 in my suburban for a few years. I had a special output shaft from Advance Adapters, and had to move the crossmember back a bit after replacing the original Turbo 350. Great combo in my opinion. If you want a lower gear ratio and lighter weight I'd go for the 241 like the other guys have recommended.

03-15-2010, 11:16 PM	#1
idastang Registered User Join Date: Oct 2009 Location: cedar city ut Posts: 34	What T-case to match a th700r4 Hi, I am looking into changing my th350/203 for a th700r4. What I am not sure about is what year trans and t-case should I be looking for? This is for a 69 short bed with a 12 bolt rear and a dana 44 up front. The engine is a 327. My goal is to have something that will cruise the hyways a little better at lower rpms. I am runing 32s and not sure what the gearing is. Is there some way to id the gearing? I know the front dana 44 is from a 76 k5 blazer based on the BOM number. I not sure if I will be able to find a matched set together so I need to know what to look for in a th700r4 and t-case. Thanks for any help.

03-16-2010, 12:09 AM	#2
timcrow00 Registered User Join Date: Mar 2009 Location: mulvane, KS Posts: 200	Re: What T-case to match a th700r4 mine is a 241 behind my 4l60e which is the same bolt pattern as your 700r4. but ive read they dont do well with tall tires so...

03-16-2010, 12:20 AM	#3
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: What T-case to match a th700r4 Yea 241s will bolt right up same as 208s is what I have heard. __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

03-16-2010, 10:48 PM	#4
munger Registered User Join Date: Nov 2009 Location: goodland,ks Posts: 217	Re: What T-case to match a th700r4 82-87 700r4s had the np208 transfer case you do not want a 82-87 700r4 they are notorius for failing unless you update them a little 87-91 suburbans had the np241c right hand drop same as 208 but only suburaban pickups has ifs and had the np241 left hand drop __________________ mitch 87 chevy short box 4wd tbi 350/built 700r4/np208 3.73s

03-16-2010, 11:12 PM	#5
USSkoval Registered User Join Date: Jul 2009 Location: West Jefferson, OH Posts: 999	Re: What T-case to match a th700r4 208 is most common behind a 700r4, but to use the 208, you will need to use the associated shifter and mini console/boot setup. To get use out of the OD without bogging it down, you will want a 3.73 gear, maybe even a 4.10 ratio. If you don't want to run the common 208 tcase, you can run a 205 from behind a th350. There is a spacer made for this that goes between the tranny and the adapter for the tcase.

03-16-2010, 11:55 PM	#6
AJs72K5 Registered User Join Date: Nov 2007 Location: South Tx Posts: 1,083	Re: What T-case to match a th700r4 The 241 is a direct bolt on to either a 700r4 or a 4l60e as mentioned. On straight axle trucks, 241s are passenger side drop. When GM went to IFS (independent front suspension), the 241s were driver side drop. I'm running one behind my 700. The 241 has two weaknesses: the aluminum case and the slip yoke on the rear output. Both are easily corrected with 1) a good skidplate and 2) and JB Conversions Slip Yoke Eliminator (SYE). Otherwise, the 241 is a great case with a deeper low gear than a 205. There are guys on CK5 wheeling 241s with 42" tires and larger. __________________ - AJ Gray Matter Build - 1972 K5 with some stuff Last edited by AJs72K5; 03-16-2010 at 11:58 PM.

03-17-2010, 08:27 AM	#7
doug70 Registered User Join Date: Nov 2005 Location: Breckenridge, texas Posts: 83	Re: What T-case to match a th700r4 There are some 241 pass side drops. I have one that I had planned to use, but I went to ford dana 60 solid axle for that truck so I stayed with the Bw4401. That Tcase is a monster but drivers drop only. 1970 cab and clip on a 97 Ford f350 frame, 427BB/nv4500, dana 60 rear too. Doug __________________ 68 CST 396, 60K original miles 70 Longhorn project 72 Stepside (150% complete) 67 Stepside project 71 RS Camaro 90% done 71 BB Corvette 50% complete 78 K5 project

03-19-2010, 01:03 PM	#8
idastang Registered User Join Date: Oct 2009 Location: cedar city ut Posts: 34	Re: What T-case to match a th700r4 Wow, this is what I like about this sight. Lots of good info on simple questions. Thanks for all who replyed and if someone has something more to add, keep it coming. I am sure this info is of help to others as well

03-20-2010, 10:21 PM	#9
Beelzeburb Devil's in the Details Join Date: Sep 2008 Location: Southern Utah Posts: 353	Re: What T-case to match a th700r4 Small world, idastang is probably 10 minutes from my house. I personally ran my original NP205 behind a 700R4 in my suburban for a few years. I had a special output shaft from Advance Adapters, and had to move the crossmember back a bit after replacing the original Turbo 350. Great combo in my opinion. If you want a lower gear ratio and lighter weight I'd go for the 241 like the other guys have recommended. __________________ '70 K10 Suburban - TBI 454, 4L80E, NP241C, Dana 60 & 44 - The 10+ Year Project Thread Datsun 240Z, 510 2 door and an old Honda motorcycle Last edited by Beelzeburb; 03-20-2010 at 10:21 PM.

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