gmc info

[Austin1]

205, not 203, totally diferent animal.

Yes I know that! but when people see a real cast iron transfer case they think right away it is a 205. 203 is not to bad of a transfer case only problem is they are full time there are two kits available to convert them lets just say you get what you pay for!Not sure what G.M put in the heavy duty in 91 but in the half and light duty 3/4 it was a np 241 great gear ratio aprox 2.7-1 in low much better than a 205 at 2-1 but case made of aluminum and with a slip yoke on the tcase end again you can get a kit to get rid of these problems! That's what I did on my 90 Blazer still running the 241 but with a Turbo 400 trans and 502 big block with 6'' lift buy getting rid of the slip yoke I gain another 4'' to help drive line angle/ The slip yoke is on the drive shaft not The tcase end, uses the same u joints as a np205 out of a 1 ton I did this almost 8 years ago I will find out the names for the Tcase adapter kit cant remember I own too many trucks!
but you might have a 241 in your truck! really not that bad of a Tcase much better than a 208 But they did not put a 208 in the trucks made in 91 that I know of. is it cast or aluminum?
Buy the way mine now has a Dana60 front with air lockers and 14 bolt rear with a detroit locker

 

[chowdozer]

Yes I know that! but when people see a real cast iron transfer case they think right away it is a 205. 203 is not to bad of a transfer case only problem is they are full time there are two kits available to convert them lets just say you get what you pay for!Not sure what G.M put in the heavy duty in 91 but in the half and light duty 3/4 it was a np 241 great gear ratio aprox 2.7-1 in low much better than a 205 at 2-1 but case made of aluminum and with a slip yoke on the tcase end again you can get a kit to get rid of these problems! That's what I did on my 90 Blazer still running the 241 but with a Turbo 400 trans and 502 big block with 6'' lift buy getting rid of the slip yoke I gain another 4'' to help drive line angle/ The slip yoke is on the drive shaft not The tcase end, uses the same u joints as a np205 out of a 1 ton I did this almost 8 years ago I will find out the names for the Tcase adapter kit cant remember I own too many trucks!
but you might have a 241 in your truck! really not that bad of a Tcase much better than a 208 But they did not put a 208 in the trucks made in 91 that I know of. is it cast or aluminum?
Buy the way mine now has a Dana60 front with air lockers and 14 bolt rear with a detroit locker

The NP208 case was available from 1981-1987 which covered the older body style. His 1991 crew is the older body style. Offhand, I would say it's a NP205 being that it's a 3500, except that he has the TH700R4 also. I don't believe any NP205's were bolted to 700R4's. I may be wrong, I just haven't seen any.

The NP203 is a good case. Best when bolted to a NP205 for a 4:1 low reduction. Then make the NP205 a twin stick.

edit: and yeah, you're right. He could have a 241 case. That's starting to get out of my time period.

old iron lives!

 

[Austin1]

The NP208 case was available from 1981-1987 which covered the older body style. His 1991 crew is the older body style. Offhand, I would say it's a NP205 being that it's a 3500, except that he has the TH700R4 also. I don't believe any NP205's were bolted to 700R4's. I may be wrong, I just haven't seen any.

The NP203 is a good case. Best when bolted to a NP205 for a 4:1 low reduction. Then make the NP205 a twin stick.

edit: and yeah, you're right. He could have a 241 case. That's starting to get out of my time period.

old iron lives!

I know I stopped looking at gm's after 90 my blazer is still the square body thats about all that is stock on it! I also like old iron my favorite being the 67-72 chevy. I am not sure if they put the 205 in a auto but who knows those years I like to call the cross over years!

 

[chowdozer]

I know I stopped looking at gm's after 90 my blazer is still the square body thats about all that is stock on it! I also like old iron my favorite being the 67-72 chevy. I am not sure if they put the 205 in a auto but who knows those years I like to call the cross over years!

I've been looking for a '69 or '70 3/4 4wd. I've passed a few up and then wonder if I'll see another?

And you're right, they did alot of strange stuff in the late 80's. early 90's on the trucks.

 

[Austin1]

I've been looking for a '69 or '70 3/4 4wd. I've passed a few up and then wonder if I'll see another?

And you're right, they did alot of strange stuff in the late 80's. early 90's on the trucks.

I think all of the big three did that but like always dodge was last to jump on the bandwagon, but one of the first to start a new trend in the mid 90s

 

[JONSSTIHL]

I am tempted to do the intake gaskets myself. but I don't really have the time to do it and I really don't have the time to do the job twice if for some reason I screw it up and it still leaks.

If I had a good how to article I might try it. It doesn't sound too complicated just have to watch out for the timing when you put the distributor back in. are people using actual gaskets or is it more common to use silicone rtv. are gm gaskets any better than aftermarket

I turned the rad. cap back a notch to not let it build up pressure and I think it may have temporarily solved the problem. and so far no overheating

I think it has a 4l80e transmission in it and I haven't had time to check if the case is alum. or iron but it is huge and I think from memory that it is iron.

any one know how the stock in dash voltmeter is wired in because it is reading quite low (just above the red) but I get 13.5v at the battery

thanks

 

[chowdozer]

I am tempted to do the intake gaskets myself. but I don't really have the time to do it and I really don't have the time to do the job twice if for some reason I screw it up and it still leaks.

If I had a good how to article I might try it. It doesn't sound too complicated just have to watch out for the timing when you put the distributor back in. are people using actual gaskets or is it more common to use silicone rtv. are gm gaskets any better than aftermarket

I turned the rad. cap back a notch to not let it build up pressure and I think it may have temporarily solved the problem. and so far no overheating

I think it has a 4l80e transmission in it and I haven't had time to check if the case is alum. or iron but it is huge and I think from memory that it is iron.

any one know how the stock in dash voltmeter is wired in because it is reading quite low (just above the red) but I get 13.5v at the battery

thanks

Yes, use gaskets. RTV is a sticky mess and doesn't clean up well. RTV on gaskets makes them slip-and-slide. I use 3M weatherstrip adhesive around the waterjackets.

The voltmeter is connected to an ignition on source. Check connections, measure voltage where the voltmeter is and maybe remove the voltmeter and hook it directly to the battery under the hood to check. Possibility the voltmeter isn't reading correctly. They aren't top quality voltmeters.

Add LMC Truck to your list of websites.
http://www.lmctruck.com/icatalog/cc/0001.asp

 

[JONSSTIHL]

I think someone all ready mentioned lmc truck parts on page one and it is all ready in my favorites but it says they are only for 1/2 and 3/4 ton pick-ups

and I'm a little confused as to where I need to draw the line since my truck is an older body style with the new model year but my best guess is that anything for an 87 would probably fit.

thanks

 

[chowdozer]

I think someone all ready mentioned lmc truck parts on page one and it is all ready in my favorites but it says they are only for 1/2 and 3/4 ton pick-ups

and I'm a little confused as to where I need to draw the line since my truck is an older body style with the new model year but my best guess is that anything for an 87 would probably fit.

thanks

Your truck is identical to a 3/4 ton with the exception of the front axle and maybe a spring or two extra and all parts from an '87 will fit. The only possible place I think you may have a problem is in the fuel system. There may have been some changes to the fuel injection from 87 to 91. But don't quote me on that. Those trucks had minor revisions from 73 to 87.