what tranny should I go with? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BLUE THUNDER · 10-05-2008, 10:13 PM

Well guys, I'm sure that this has been discussed at least a couple of times already but...... I'm in the middle of pulling out my Th350. After i got the new motor in and running the tranny decided to dump all its fluids on my garage floor. (BTW, I also posted this question on the drivetrain section with 0 answers so far). I figure my blazer and jimmy bro's wld have answers for me. I'm planning on some light wheeling, road trips, and possibly towing an R.V. Since I've never driven my Blazer I don't know what the rpm's are at highway speeds. I've heard at about 70mph they are pretty high. If anyone knows exactly what rpm it is please let me know. My questions are 1) is the Th350 strong enough for what i have planned? I shld mention that it has a 4" lift and 33's with 3.73 gears. My second question is what is the benefit of going with a Th400 or 700r4. How difficult are these swaps if i wanted to retain the np205? I really need some feedback to make a good decision. Thanks, Mario

Critter · 10-05-2008, 10:55 PM

The 400 would be much stronger, and the 700r4 would be much better for a daily driver. The problem with either one of them is the high cost of getting them adapted to the NP205. Realistically, I would think that you are talking about a good $1,000 to make it happen unless you just got lucky and free parts fell into your lap. Not to mention the cost of the new tranny. A TH350 can handle basically everything you have in mind.

One thing bothered me though. What type of RV are you talking about? Honestly, anything other than a small pop-up would probably be a little dangerous with a lifted K5. Their short wheel base combined with a lift makes them a little unstable IMHO.

Not trying to discourage you or anything, just wanting you to see all sides of the issue. Believe me I have gone through the same thoughts, so far I can't justify the cost when I have soooo many other places that my Blazer needs attention!!!

BLUE THUNDER · 10-05-2008, 11:11 PM

What do i need to adapt the Th400 or the 700r4 to the np205? As far as the rv, something about 4000 lbs or less. I could probably tow it with my Jeep Grand Cherokee.

vtblazer · 10-06-2008, 05:48 AM

Fist suggestion would be to use the search function, tons of great info has already been spread throughout these pages.

Secondly...what's your 'real' budget?
This subject can get pricey fast.

A th-350 can be built to handle anything.
A th-400 is stronger in stock form but uses a lot more HP to make it turn.
A 700r is a great all around tranny with the right basic mods performed.

The 205 may be the stoutest out there but is it always the right choice?

...there's a world of option's out there for you to choose from.

BLUE THUNDER · 10-06-2008, 09:51 AM

Is there some kind of adapter for the 700r4 to mate it to the 205? The 700r4 has an overdrive right? For those of you guys that still have the th350, how do you like 'em? Do they tow well? Do they run well for daily drivers?

vtblazer · 10-06-2008, 10:03 AM

Quote:

Originally Posted by BLUE THUNDER

Is there some kind of adapter for the 700r4 to mate it to the 205? The 700r4 has an overdrive right? For those of you guys that still have the th350, how do you like 'em? Do they tow well? Do they run well for daily drivers?

Over drive is your friend.

Some basic tranny specs here for ya to check out:
http://www.race-track.com/news.asp?TOPIC_ID=532

Jtrux · 10-06-2008, 05:20 PM

Quote:

Originally Posted by BLUE THUNDER

Is there some kind of adapter for the 700r4 to mate it to the 205? The 700r4 has an overdrive right? For those of you guys that still have the th350, how do you like 'em? Do they tow well? Do they run well for daily drivers?

Come on now, TH350's have been around since the begining of time. If they didn't work well they would obsolete by now. If your grand cherokee can pull it so can your blazer. The TH350 is a stronger tranny than what's in your jeep.

Yes the 700R4 is a good tranny and yes it's an overdrive but if you're looking to do this in a timely manner within a reasonable budget you need to just pull the 350 , rebuild it and go with it, you'll be happy as hell with it.

Things to consider if you do decide to in fact go with one of the other trannys (there is probably more but i'm just naming the basics)

Crossmember relocation

Shifter linkage

Downshift linkage (400 doesn't have one, not sure on the 700)

Cooler lines (not sure but they might be in different locations, sizes, etc)

Getting driveshafts shortened/lengthened (more $$$$$)

Finding a core or you can buy them already rebuilt from certain suppliers but are you ready to spend that kind of money, probably anywhere from a grand on up to 1500 or so depening on type and how much goodies are in it.

Adapting it to your xfercase. This isn't usually just a bolt in and go deal, the input shaft on your 205 will more than likely need to be swapped out. Also a $$$$$ thing, there are factory 400/205 adapters out there and they can be had for a hundred bucks or so but i've heard they are prone to cracking so you might not be buying a good one. The aftermarket does offer a adapter for the 700 (search is your friend) and I think they are close to 300 bucks.

You can see the list growing and growing. The things I listed you already have for your 350. You also told me the other night how you would like to drive your blazer soon. You've owned it for a while now and just recently got the motor running so if you go yanking out the tranny and trying to swap it out for some other kind I can only imagine how long it will be til it's moving under it's own power. Stick with the 350, you won't be disappointed.

If you pull the 350 and have it rebuilt ( you can find deals out there but it would probably cost anywhere from 400 to 700 maybe???) you'll be on the road a lot quicker than if you start doing any custom stuff to it. The 700 swap would realistically cost you 2000 or better.

AJs72K5 · 10-06-2008, 06:33 PM

Josh pretty well nailed it. If you've followed my build, you can see the to-do list is by no means short to put in the 700r4/241. Sure you can run a 205 with the 700r4, but in what you'll spend on adapters (Advance Adapters) you're better off going with a 241 with the way you're gonna drive it.

I'd really recommend getting your TH350 rebuilt. Remember, you haven't even driven this rig yet! Any 700r4 swap can be done, but will add several months at a minimum to your timeline...which in "Mario-time" equals a couple of years

vtblazer · 10-06-2008, 07:48 PM

If your on a budget monetarily or time-wise, go th-350 and save big on both.

I'd bet you could find a working 'take out' tranny for a couple/few hundred bucks and be done with it.

**Tom Vogel** · 10-06-2008, 11:31 PM

Id rebuild the T350. Its lighter and takes less power to run and can be built strong. If you could put a Gear Vendors overdrive in as well, youd really be in the drivers seat.

AJs72K5 · 10-07-2008, 08:10 AM

Quote:

Originally Posted by Tom Vogel

Id rebuild the T350. Its lighter and takes less power to run and can be built strong. If you could put a Gear Vendors overdrive in as well, youd really be in the drivers seat.

The Gear Vendors kit is interesting...but big $$$$$. It's also really too long for a 4x4. His rear shaft would be about 2 feet long and have an obscene pinion angle.

BLUE THUNDER · 10-07-2008, 11:23 PM

Well guys, I'm gonna go with the rebuild for now. I've got a place to rebuild it with a warranty for $350.00. Not bad for rebuild kit, and torque converter, and a 1 year warranty. It wld be a bench job, so I wld do the r&i (remove and install). I used to send this guy a lot of work so I got a good deal. I do have one question, shld I get a shift kit put on when I have iv rebuilt?

**special-K** · 10-08-2008, 09:10 AM

The TH350 was in Custom Campers,Suburban tow rigs,and K/20s as well as Blazers.They can take it.If I was going for o/d I`d go for the later/lighter transfer case that came it.If I wanted tough I`d stay away from o/d and use the ole 205.

Jtrux · 10-08-2008, 04:16 PM

Quote:

Originally Posted by BLUE THUNDER

Well guys, I'm gonna go with the rebuild for now. I've got a place to rebuild it with a warranty for $350.00. Not bad for rebuild kit, and torque converter, and a 1 year warranty. It wld be a bench job, so I wld do the r&i (remove and install). I used to send this guy a lot of work so I got a good deal. I do have one question, shld I get a shift kit put on when I have iv rebuilt?

I would just build it stock for your application.

PanelDeland · 10-12-2008, 08:32 AM

I would build it stock or maybe heavy duty and add a auxilary tranny cooler.Temp is usually the worst enemy of an auto.Towing will cause more heat.

BLUE THUNDER · 10-12-2008, 09:41 AM

Thanks guys, I have decided to build it stock and see how it does. Later, Mario.

vtblazer · 10-12-2008, 10:04 AM

Quote:

Originally Posted by PanelDeland

add a auxilary tranny cooler.Temp is usually the worst enemy of an auto.Towing will cause more heat.

No brain-er.

Don't even ponder whether or not to do it.

nrb's70gmc · 10-12-2008, 10:14 PM

checout this site thay sell any adapter you could possibly want or think of http://www.advanceadapters.com/

10-05-2008, 10:13 PM	#1
BLUE THUNDER Registered User Join Date: May 2007 Location: San Antonio Posts: 993	what tranny should I go with? Well guys, I'm sure that this has been discussed at least a couple of times already but...... I'm in the middle of pulling out my Th350. After i got the new motor in and running the tranny decided to dump all its fluids on my garage floor. (BTW, I also posted this question on the drivetrain section with 0 answers so far). I figure my blazer and jimmy bro's wld have answers for me. I'm planning on some light wheeling, road trips, and possibly towing an R.V. Since I've never driven my Blazer I don't know what the rpm's are at highway speeds. I've heard at about 70mph they are pretty high. If anyone knows exactly what rpm it is please let me know. My questions are 1) is the Th350 strong enough for what i have planned? I shld mention that it has a 4" lift and 33's with 3.73 gears. My second question is what is the benefit of going with a Th400 or 700r4. How difficult are these swaps if i wanted to retain the np205? I really need some feedback to make a good decision. Thanks, Mario

10-05-2008, 10:55 PM	#2
Critter Future TOTM Winner Join Date: Aug 2006 Location: Bulverde, TX Posts: 2,692	Re: what tranny should I go with? The 400 would be much stronger, and the 700r4 would be much better for a daily driver. The problem with either one of them is the high cost of getting them adapted to the NP205. Realistically, I would think that you are talking about a good $1,000 to make it happen unless you just got lucky and free parts fell into your lap. Not to mention the cost of the new tranny. A TH350 can handle basically everything you have in mind. One thing bothered me though. What type of RV are you talking about? Honestly, anything other than a small pop-up would probably be a little dangerous with a lifted K5. Their short wheel base combined with a lift makes them a little unstable IMHO. Not trying to discourage you or anything, just wanting you to see all sides of the issue. Believe me I have gone through the same thoughts, so far I can't justify the cost when I have soooo many other places that my Blazer needs attention!!! __________________ 72 Chevy CST K5 HIGHLANDER BLAZER Getting a 6.0,NV4500,NP205,14BFF (Currently laying all over the place in little pieces) 72 Chevy swb step-side "LS" 6.0 Here's a build thread of sorts 2002 HD2500 Crew Cab, 8.1L Allison 4x4 Daily Driver Check it out www.lsdyno.com

10-05-2008, 11:11 PM	#3
BLUE THUNDER Registered User Join Date: May 2007 Location: San Antonio Posts: 993	Re: what tranny should I go with? What do i need to adapt the Th400 or the 700r4 to the np205? As far as the rv, something about 4000 lbs or less. I could probably tow it with my Jeep Grand Cherokee.

10-06-2008, 05:48 AM	#4
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	Re: what tranny should I go with? Fist suggestion would be to use the search function, tons of great info has already been spread throughout these pages. Secondly...what's your 'real' budget? This subject can get pricey fast. A th-350 can be built to handle anything. A th-400 is stronger in stock form but uses a lot more HP to make it turn. A 700r is a great all around tranny with the right basic mods performed. The 205 may be the stoutest out there but is it always the right choice? ...there's a world of option's out there for you to choose from.

10-06-2008, 09:51 AM	#5
BLUE THUNDER Registered User Join Date: May 2007 Location: San Antonio Posts: 993	Re: what tranny should I go with? Is there some kind of adapter for the 700r4 to mate it to the 205? The 700r4 has an overdrive right? For those of you guys that still have the th350, how do you like 'em? Do they tow well? Do they run well for daily drivers?

10-06-2008, 06:33 PM	#8
AJs72K5 Registered User Join Date: Nov 2007 Location: South Tx Posts: 1,083	Re: what tranny should I go with? Josh pretty well nailed it. If you've followed my build, you can see the to-do list is by no means short to put in the 700r4/241. Sure you can run a 205 with the 700r4, but in what you'll spend on adapters (Advance Adapters) you're better off going with a 241 with the way you're gonna drive it. I'd really recommend getting your TH350 rebuilt. Remember, you haven't even driven this rig yet! Any 700r4 swap can be done, but will add several months at a minimum to your timeline...which in "Mario-time" equals a couple of years __________________ - AJ Gray Matter Build - 1972 K5 with some stuff Last edited by AJs72K5; 10-06-2008 at 10:22 PM.

10-06-2008, 07:48 PM	#9
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	Re: what tranny should I go with? If your on a budget monetarily or time-wise, go th-350 and save big on both. I'd bet you could find a working 'take out' tranny for a couple/few hundred bucks and be done with it.

10-06-2008, 11:31 PM	#10
Tom Vogel 2WD Jimmy Join Date: Mar 2005 Location: Davis County, Utah Posts: 2,563	Re: what tranny should I go with? Id rebuild the T350. Its lighter and takes less power to run and can be built strong. If you could put a Gear Vendors overdrive in as well, youd really be in the drivers seat.

10-07-2008, 11:23 PM	#12
BLUE THUNDER Registered User Join Date: May 2007 Location: San Antonio Posts: 993	Re: what tranny should I go with? Well guys, I'm gonna go with the rebuild for now. I've got a place to rebuild it with a warranty for $350.00. Not bad for rebuild kit, and torque converter, and a 1 year warranty. It wld be a bench job, so I wld do the r&i (remove and install). I used to send this guy a lot of work so I got a good deal. I do have one question, shld I get a shift kit put on when I have iv rebuilt?

10-08-2008, 09:10 AM	#13
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,862	Re: what tranny should I go with? The TH350 was in Custom Campers,Suburban tow rigs,and K/20s as well as Blazers.They can take it.If I was going for o/d I`d go for the later/lighter transfer case that came it.If I wanted tough I`d stay away from o/d and use the ole 205. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

10-12-2008, 08:32 AM	#15
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: what tranny should I go with? I would build it stock or maybe heavy duty and add a auxilary tranny cooler.Temp is usually the worst enemy of an auto.Towing will cause more heat. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

10-12-2008, 09:41 AM	#16
BLUE THUNDER Registered User Join Date: May 2007 Location: San Antonio Posts: 993	Re: what tranny should I go with? Thanks guys, I have decided to build it stock and see how it does. Later, Mario.

10-12-2008, 10:14 PM	#18
nrb's70gmc Registered User Join Date: Sep 2008 Location: magalia,ca Posts: 366	Re: what tranny should I go with? checout this site thay sell any adapter you could possibly want or think of http://www.advanceadapters.com/ __________________ 1970 2wd 3/4 ton- 2004 crate 350 thorley tri-y headers-edelbrock performer eps manifold 600cfm performer carb, crane cams energizer cam,lifters, dual 2.5 magnaflows, mallory HEI, powermaster 140 amp altenator, griffen aluminum radiator.(8 MPG)



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