Few Questions for a possible future project

[mrnapolean1]

1. I have an 1987 Chevrolet R10 Pickup with a 4.3 V6 in it. I want to put a transmission with Overdrive in it so I can get better Gas mileage out of my square. Whats the best way of doing this?

2. I am unsure what transmission is in it right now. How could I tell what Transmission is in it right now?

3. Would a 700R4 from like a '90 to '94 Chevrolet/GMC pickup work?

4. What would I do for the torque converter lockup (the little 4 pin square plug)?

5. What would I do for the speedometer?

6. What about the driveshaft? Am I going to have to get a different one?
Or can I use my existing one?

And If possible could you link me to all necessary parts I will need.

 

[HotRodPC]

You don't have OD now? I know some v6's came with a Th400 which is a 3 speed auto. 700r4 up to 92 is what you want' 93 up are Electronic Controlled and ECM operated. As far as speedo, just make sure you have whatever speedo type drive you have, matches the output shaft on the 700r4. There is only 2 option. Either cable driven, or Electronic. Yep, you will have to cut your dshaft.

 

[mrnapolean1]

You don't have OD now? I know some v6's came with a Th400 which is a 3 speed auto. 700r4 up to 92 is what you want' 93 up are Electronic Controlled and ECM operated. As far as speedo, just make sure you have whatever speedo type drive you have, matches the output shaft on the 700r4. There is only 2 option. Either cable driven, or Electronic. Yep, you will have to cut your dshaft.

No I do not have OD, Hence the purpose of this project.

How can I tell what transmission I have now?

BTW The truck is a single cab short wheel base with a stepside bed.

 

[hinkv10]

Take a picture of the pan on the trans and post it up. Easy to figure it out

 

[mrnapolean1]

Take a picture of the pan on the trans and post it up. Easy to figure it out

Like this:

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This was taken from the drivers side.

 

[gpmorgan]

https://www.google.com/search?q=gm+..._Csu4kQf3qYC4DQ&ved=0CDUQsAQ&biw=1241&bih=606

 

[mrnapolean1]

https://www.google.com/search?q=gm+..._Csu4kQf3qYC4DQ&ved=0CDUQsAQ&biw=1241&bih=606

According to your results and my picture I have a TH400. Someone please confirm for me.

 

[gpmorgan]

Yes, acording to the pics, you have a th400.

 

[mrnapolean1]

Yes, acording to the pics, you have a th400.

OK say it is a TH400, How much Modification will I have to do to get a 1990s 700R4 with overdrive to fit and work in my 1987 R10 pickup?

 

[Boone83K10]

driveshaft, trans mount, detent cable, speedometer cable/electronics... brute man force to lift it. lol


actually, you probably getting better MPG with the 400 depending on your rear gear ratio. if you have a 3.08 or something, then an OD will get worse because you don't have enough powerrrrrrr to maintain speed in OD, and will have constant cycling. My truck has a 700r4 with 3.08 and it's barely above idle going about 55 which is the fastest I go around them there hills I live in.

 

[89Suburban]

 

[HotRodPC]

Not really any need for electronics for the 7000r4. Just the lock up converter is all it'll need and he can get that signal from a Vac Switch, or if he's still TBI, get the signal from the ECM either way works fine.

Because he's V6, I'd say he prolly would get a little better mpg with the 700r4, but he might not get full use of the OD if he's a tall gear like Boone suggested. 700r4 will have a better first gear for around town driving, weigh a bit less and rob a few less hp. But, you're giving up brute overkill strength. If you do it, and have 3.08's or 2.73's you probably won't use OD hardly at all. Like 80mpg plus.

 

[mrnapolean1]

driveshaft, trans mount, detent cable, speedometer cable/electronics... brute man force to lift it. lol


actually, you probably getting better MPG with the 400 depending on your rear gear ratio. if you have a 3.08 or something, then an OD will get worse because you don't have enough powerrrrrrr to maintain speed in OD, and will have constant cycling. My truck has a 700r4 with 3.08 and it's barely above idle going about 55 which is the fastest I go around them there hills I live in.

How would I be able to tell what gear ratio I have?
I think its 3.10 but I am not for sure.

 

[mrnapolean1]

My dad (the person that had this truck before me) said it has a metric transmission in it.