Took the 64 Shortwide on the Highway

[JRBECK64]

This was the first time I took the truck on the highway since it was restored. I ran it up to 55 which was comfortable and then I pushed it up to 65 and it was still smooth but you could tell the engine was reving a little more than you would want it to at that speed. I ran it for about 20 miles at about 60 and it seemed like thats the comfortable speed for this truck on the highway. I ordered a butt load of parts from Wes in Olympia Wa. For the 67 Shortwide I am restoring and I think I am going to take it for a cruise up I-5 to pick them up when they all arrive. Looks like that maybe 6 weeks before that happens but with my Sons 69 Long Fleet in the middle of bodywork who's in a big hurry? Im thinking about looking into possibly putting a 700R4 in this thing to make it a bit more Drivable on the freeway. It has 3.73/1 gears in the back and with the size tires it has on it with a .76 OD it would put the rpms at about 2300 at 65 MPH and I figure it is reving a little over 3K the way its set up now with the TH400. I think I could do the 700R for cheaper than changing out the gear set. What do you think? Any Opinions?

JRBECK64

[likaroc13]

from what i've read & what i've been told, the 3.73's are an ideal gear for the 700R4...one of the first things on my list will be converting to 5-lug...i'm debating whether to keep my Powerglide & run 3.08's, or switch to the 700R4 & 3.73's...right now money is a big factor, so i'm leaning toward keeping the P-glide...not positive, but i think i have 3.73's in the factory rear, & it really hums when you get to 55mph or so...if i were in your shoes, i'd just do the 700R4 swap when you get a chance

[blackedoutharley]

I think you could do the rear gears for less than a 700R4.

[JRBECK64]

Originally Posted by likaroc13

from what i've read & what i've been told, the 3.73's are an ideal gear for the 700R4...one of the first things on my list will be converting to 5-lug...i'm debating whether to keep my Powerglide & run 3.08's, or switch to the 700R4 & 3.73's...right now money is a big factor, so i'm leaning toward keeping the P-glide...not positive, but i think i have 3.73's in the factory rear, & it really hums when you get to 55mph or so...if i were in your shoes, i'd just do the 700R4 swap when you get a chance

likaroc13,
My only dilema with this swap is I know how tough these old TH400's are and I have heard mixed reviews on the 700R4 and 4l60E. But I can tell you this is not a race truck but at the same time its not a slouch either. That being said it has a mild 69 327 in it probably pushing 300HP with the upgrade done to it. I guess I need to start doing my homework on the pro's and con's on the 700R4 and do the math from there. I wonder if you have to change the length of the driveshaft or the yoke if you change to a 700R4? Guess the other question is do you have to change the Tranny Crossmember if you change from a TH400 to a 700R4? Lots of Questions.
Thanks for giving your opinion.
JRBECK64

[JRBECK64]

Originally Posted by blackedoutharley

I think you could do the rear gears for less than a 700R4.

blackedoutharley,
Around here it cost about $600 to $700 to have the gears changed and the Diff rebuilt. If I do score a 700R4 I am hoping to find one in a running vehicle so I can see what I am getting or at least drive it before I buy it. If I had all the know how to change out the gear set myself I would but I have never done one and I know you need some dial guages and if they are not shimmed properly they wont be right. I guess I need to do some research on what a 700R4 with low mileage cost and again do the math from there. Thanks for posting your opinion.

JRBECK64

[steverino66]

I put a 700r4 in my 66 El Camino with 3:36 rear, it's been great for 2 years. I spent about the same amount on the trans as I did rebuilding the rear in the 66 C10 with 5-lug axle swap, but I'm less intimidated by the trans swap. It's really nice when you hit 4th gear and the tach drops way below 3k, with a 4th-gear lockup switch/converter you get another couple hundred rpm drop.
My 700r4 is 3" longer than the TH350 so I shortened the driveshaft but I think the long tail 350 is the same? Crossmember moved back on the frame but works. Be sure you have the correct TV cable/connector parts for your carb, that's critical. I had to go to Bowtieoverdrives.com for my Holley 4bbl (pricey).

[JRBECK64]

Originally Posted by steverino66

I put a 700r4 in my 66 El Camino with 3:36 rear, it's been great for 2 years. I spent about the same amount on the trans as I did rebuilding the rear in the 66 C10 with 5-lug axle swap, but I'm less intimidated by the trans swap. It's really nice when you hit 4th gear and the tach drops way below 3k, with a 4th-gear lockup switch/converter you get another couple hundred rpm drop.
My 700r4 is 3" longer than the TH350 so I shortened the driveshaft but I think the long tail 350 is the same? Crossmember moved back on the frame but works. Be sure you have the correct TV cable/connector parts for your carb, that's critical. I had to go to Bowtieoverdrives.com for my Holley 4bbl (pricey).

steverino66,
I currently have a 200R4 and it came out of a car that I drove and it was tight. That being said I think I am going to use it in my Sons 64. I know where the car is that it came out of and What I think I am going to do is go get all the bracketry from that car and adapt it to his truck. I appreciate your insight on this and I agree with you that I would rather tackle the Tranny than mess with the Diff.
Thanks,
JRBECK64

[steverino66]

I've asked some of the other guys here, and I don't think you can expect a huge mileage gain with the truck (rolling brick aerodynamics); my Elco went from 13.5 to 16.8 mpg highway, from 3400rpm to 2200 at 70mph, whereas 700r4 60-66 C10 guys have said more like 11-12 mpg even with the overdrive, but it's still a lot less work under the hood, way more comfortable drive. Good luck.

[awire007]

Originally Posted by JRBECK64

likaroc13,
My only dilema with this swap is I know how tough these old TH400's are and I have heard mixed reviews on the 700R4 and 4l60E. But I can tell you this is not a race truck but at the same time its not a slouch either. That being said it has a mild 69 327 in it probably pushing 300HP with the upgrade done to it. I guess I need to start doing my homework on the pro's and con's on the 700R4 and do the math from there. I wonder if you have to change the length of the driveshaft or the yoke if you change to a 700R4? Guess the other question is do you have to change the Tranny Crossmember if you change from a TH400 to a 700R4? Lots of Questions.
Thanks for giving your opinion.
JRBECK64

If you go with the 700r4 you will need to have your driveshaft shortened a few inches (about $100), and you will also likely need to cut out your existing transmission mount crossmember & fabricate a new one. I could be wrong since you already have the 400 you may not need to. Mine had the original 3 speed that came with the truck so the 700 r4 was much larger & wouldn't fit through the hole. I also ended up going with a B&M floor shifter instead of trying to link up the shifter on the tree.

[JRBECK64]

Originally Posted by awire007

If you go with the 700r4 you will need to have your driveshaft shortened a few inches (about $100), and you will also likely need to cut out your existing transmission mount crossmember & fabricate a new one. I could be wrong since you already have the 400 you may not need to. Mine had the original 3 speed that came with the truck so the 700 r4 was much larger & wouldn't fit through the hole. I also ended up going with a B&M floor shifter instead of trying to link up the shifter on the tree.

awire007,

When I told my Son we were going to do this I kind of forgot about needing an extra shift detent being its a 4 speed transmission. I like the locar shifters that go on the floor but that means I need to do some surgery to the steering column to get rid of the shifter on the column. Allways something that you forget when doing a project like this one. Thanks for the info but after talking with my local tranny guy he told me that I might have to unbolt the tranny crossmember and move it back then drill new holes if the tranny is to long. I am going to set the 200R4 that I have next to the 400 that I pull out of the truck and then do some comparisons to where the mounts are. Then do the mods from there. Again thanks for the info.

JRBECK64