Increase MPG by 50-80% with a cold vapor fuel system?

[kikkegek]

Originally Posted by Edahall

The 700R4 was used for both two and four wheel drive. The case is different between the two but you can use the four wheel drive 700R4 on a 2 wheel drive vehicle. However, you can't use the two wheel drive 700R4 on a 4 wheel drive vehicle. My 1982 Suburban has a 700R4 and 6.2L diesel engine and it gets 30 mpg on the highway.

wow! nice mileage.

how do you recognise a 4wd version from a 2wd?

[McSwine]

Originally Posted by bigwheel15

Set it up in reverse and you have a time machine.

I had one of those deer whistles but put it on backwards by mistake.

Looked in my rearview mirror and had a whole freek'n herd following me.

[Goldfinger]

4wd 700r4 has a short shaft while the 2wd version is much longer

[kikkegek]

Originally Posted by Goldfinger

4wd 700r4 has a short shaft while the 2wd version is much longer

so, can I buy any 700R4 and do I need to find a seperate longer shaft, or is that directly connected to it?

[Edahall]

Originally Posted by kikkegek

so, can I buy any 700R4 and do I need to find a seperate longer shaft, or is that directly connected to it?

I would highly recommend looking for a 2wd version 700R4. The 4x4 tranny has a shorter output shaft and will not work in a 2wd application. You would need to locate and install a 2wd shaft for this to work. You need to tear into the tranny to do this. It can be done but it's more work then it's worth.

[Edahall]

Originally Posted by kikkegek

wow! nice mileage.

how do you recognise a 4wd version from a 2wd?

Even a heavy Suburban can get good fuel economy if equipped correctly. Only problem is in the states, diesel has been significantly more expensive than gasoline the last while.

If you do put in a 700r4, make sure you get a 1987-1993 tranny. They were a better overall unit.

2wd


4wd

[kikkegek]

@Edahall: thanks for the info.

sorry for the misunderstanding guys. I have a 4WD. So I will need to look for a 4WD version.

probably no way I can get one over here in the Netherlands.

Anybody got a good one for sale here?

[GmtGmt]

Try Osby Skrotten en sweden Peter is always ready to help

http://www.bildelarosby.se/en

[69CST4x4SWB]

How hard is it to swap out my old 4 speed with granny low to a 6 speed in my '69 K10 which I believe has the NP205 transfer case? I hope I got that right! Also, what could I get the 6 speed out of so I know what to look for? Thanks!

[kikkegek]

I ended up swapping my TH400-NP208 for a perfect swap in one day for a TH700R4 with NP208...even the crossmember was already in the correct spot.

waiting for first mileage results now

[Edahall]

Originally Posted by 72_GMC_Sierra_Grande

How hard is it to swap out my old 4 speed with granny low to a 6 speed in my '69 K10 which I believe has the NP205 transfer case? I hope I got that right! Also, what could I get the 6 speed out of so I know what to look for? Thanks!

Are you wanting a 6 speed manual or 6 speed automatic? I'm using an NV5600 6 speed manual in my 1990 Suburban with a NP205. There are others such G56 and ZF6. The NV5600's were offered in Dodge Cummins trucks from about 99-03. Afterwards, they went to G56.

[andrewmp6]

Have you looked in to a diesel swap tho ?

[rwhit57]

Originally Posted by McSwine

I had one of those deer whistles but put it on backwards by mistake.

Looked in my rearview mirror and had a whole freek'n herd following me.

Buddy brought me his Blazer one time to repair, he hit a deer at about 60mph. I looked down when it arrived and saw those little chrome deer whistles mounted to the front bumper, and I said "Looks like those worked just fine, the deer avoided the bumper completely and took out the grille, both headlights, the hood, the windshield, and one fender. Gotta get me some of them"

[69CST4x4SWB]

Originally Posted by Edahall

Are you wanting a 6 speed manual or 6 speed automatic? I'm using an NV5600 6 speed manual in my 1990 Suburban with a NP205. There are others such G56 and ZF6. The NV5600's were offered in Dodge Cummins trucks from about 99-03. Afterwards, they went to G56.

Yeah, looking for a 6 speed manual that will bolt right up to my NP205 and hoping to not have to make any or at least little modifications to anything!!! Maybe what I need is a complete unit trans/transfer case and just swap it all out together!?

[Edahall]

Originally Posted by 72_GMC_Sierra_Grande

Yeah, looking for a 6 speed manual that will bolt right up to my NP205 and hoping to not have to make any or at least little modifications to anything!!! Maybe what I need is a complete unit trans/transfer case and just swap it all out together!?

The NV5600 is one of the transmissions that will bolt up to an NP205. However, it's still much longer than the SM465 4 speed manual in your truck. That would mean making driveline changes and moving the crossmember back. You'll also need an adapter from someplace like Advanced Adapters to be able to mount it to your engine.

The other option might be to use a 6-speed ZF S6-650 manual out of a 2001 or later Chevy 4x4 truck with the 8.1L. The advantage here is it would bolt right up to your 350. However, GM didn't sell many 8.1's to begin with and finding one with a 6 speed manual is going to be even harder. Most people opted for the Duramax and Allison transmission.

Why are you interested in a 6 speed? Do you do a lot towing? If you do a lot of heavy towing, having that close ratio makes a huge difference. If you're just looking for that extra gear for better cruising, consider another option. Install 3.08 or 2.73 gears and stay with your 4 speed. My 72 Chevy 4x4 4- speed has 3.08 gears and it cruises very nicely at 75 mph.

[69CST4x4SWB]

Originally Posted by Edahall

The NV5600 is one of the transmissions that will bolt up to an NP205. However, it's still much longer than the SM465 4 speed manual in your truck. That would mean making driveline changes and moving the crossmember back. You'll also need an adapter from someplace like Advanced Adapters to be able to mount it to your engine.

The other option might be to use a 6-speed ZF S6-650 manual out of a 2001 or later Chevy 4x4 truck with the 8.1L. The advantage here is it would bolt right up to your 350. However, GM didn't sell many 8.1's to begin with and finding one with a 6 speed manual is going to be even harder. Most people opted for the Duramax and Allison transmission.

Why are you interested in a 6 speed? Do you do a lot towing? If you do a lot of heavy towing, having that close ratio makes a huge difference. If you're just looking for that extra gear for better cruising, consider another option. Install 3.08 or 2.73 gears and stay with your 4 speed. My 72 Chevy 4x4 4- speed has 3.08 gears and it cruises very nicely at 75 mph.

Actually, looking for anything I can do to improve my current MPG of 8.5 as it is my daily driver right now and will be for quite a while! Of course cost in gaining MPG is also a factor. Any ideas? Already replaced ALL ignition parts which gave me 1.5 MPG gain. The Edelbrock carb (not sure of size) with manual choke seems to be working pretty good although if it sets for more than a few days, it is hard to start! As for the gears, not sure what they are either! Pretty low though since if I do a rolling stop at a stop sign, I can leave it in 3rd gear with no problem! Thanks

[Edahall]

Originally Posted by 72_GMC_Sierra_Grande

Actually, looking for anything I can do to improve my current MPG of 8.5 as it is my daily driver right now and will be for quite a while! Of course cost in gaining MPG is also a factor. Any ideas? Already replaced ALL ignition parts which gave me 1.5 MPG gain. The Edelbrock carb (not sure of size) with manual choke seems to be working pretty good although if it sets for more than a few days, it is hard to start! As for the gears, not sure what they are either! Pretty low though since if I do a rolling stop at a stop sign, I can leave it in 3rd gear with no problem! Thanks

Look for some 2.73 gears. They were common in the late 70's and early 80's before overdrive came out. They often sell for less than the other gear options. With 2.73's, 4th gear will act like an overdrive and 1st gear actually becomes usable to start off in. I get about 15 mpg with my 72 GMC 4x4. It's got 3.08's, 350 engine and a 4 speed manual.

[69CST4x4SWB]

Originally Posted by Edahall

Look for some 2.73 gears. They were common in the late 70's and early 80's before overdrive came out. They often sell for less than the other gear options. With 2.73's, 4th gear will act like an overdrive and 1st gear actually becomes usable to start off in. I get about 15 mpg with my 72 GMC 4x4. It's got 3.08's, 350 engine and a 4 speed manual.

Sounds good!!! Stupid question??? Do you have to match the front and rear gears? Also, If I am hearing you correctly, the 2.73's are in the used market only? Sorry, my brain is foggy... been battling severe illness over the last month! Thanks

[Edahall]

Originally Posted by 72_GMC_Sierra_Grande

Sounds good!!! Stupid question??? Do you have to match the front and rear gears? Also, If I am hearing you correctly, the 2.73's are in the used market only? Sorry, my brain is foggy... been battling severe illness over the last month! Thanks

Yes you'll have to match the front and rear gears otherwise you won't be able to use your 4 wheel drive.

2.73's are only found in the used market from what I know. However, you could regear your current axles to 2.73's but it'll most likely cost you more money than just buying a set of 2.73 axles. If you've got 3.73's I'm sure you could trade with somebody and come out ahead.

[69CST4x4SWB]

Sounds like I've got a project on the horizon!!! Thanks