4 speed auto

[erik monza]

Please help

I have an old tired th 350 3 speed automatic in my 262 - 1976 Monza with a 2.56 rear end

I am installing a 235 - 250 HP - 305 TPI and I would like a 4 speed auto to finish the update

Everybody want to sell me what they have in stock, rather than the one that is best for me, I afraid.

This is not a big power engine, but with a 4 speed auto, I hope to get the mileage about 25 miles / gallon, a rpm of about 1800 - 1900 doing 110km/h for the motorway, rear tire is 225/60 -15, please advice.

I think a lock up speed of 1750 rpm would be right and some people think that I should shift down to 3rd in city driving or only have a lock up function on when lever is in 4 gear.

I was thinking th200R4 myself, as it has the same size and fits the same length, but everybody wants to sell me 4L60 or 4L60e, but I think that it just because they have it in stock all ready.

I really need advice from somebody that have no gain from recommending either one.

Thanks from Erik

[72 SS PNL]

behind a TPI motor would have been a 700r4 , which later turned into the 4l60 then the 4l60e , the E you can not use as its all electric

the one advantage of the 700r4 is the deeper 1st gear ratio , over the 200 4r's , which would be nice with the 2.56 rear gear with use of a taller rear tire , while a shorter rear tire would like the 22 4r better

both trans missions are a little bulky , lock up for tq is usually done from the pcm for the TPI , so stall speed is your selectable choice not lock up speed

[spencerforhire]

The torque converter lock up on either the 200 or 700 is easily handled with a simple toggle switch for manual control or with the proper brake switch and a vacuum switch for automatic control. Avoid the 4L60 unless you want to spend big money on a separate computer just to run it..

[283vega]

Go with the 200r4 if you can find one

[cacmanjr]

I have a 2004R in my Skyhawk. Issues are: TV cable, custom crossmember to mount torque arm and trans, and shift linkage. It does fit nicely in place of the TH350 and your stock driveshaft will fit.

[cosvega76]

I like the 200-4R in my Vega. It replaced a TH350. I had to relocate the rear crossmember and shorten the driveshaft. I've heard from other members that tunnel mods are needed for a TH700. The only real issue I had was to run the speedo cable through the interior, under the carpet, since the drive location on the trans was so close to the tunnel. I probably could have used a 90-degree adapter but I took the cheap way out.

Chuck

[cammerjeff]

I also like the 200R4 in my Sunbird wagon, as already stated I was able to reuse my driveshaft and Yoke, had to make a crossmember with a mount for the Torque arm, and I ran a 90 degree adaptor that I had to get around the Speedo Cable issue, I use a B&M lock up kit as I personally do not like the vacuum switch system and I kept forgetting to switch off the manual toggle switch when coming off the highway,

I do have a 700R4 mount available as I will not be using it.

[erik monza]

Thanks all

I went with the th700R4 as it was used behind a 305 TPI and it is easy to get over here.

I had to extend - build a mount for the trans cross member and shorten the driveshaft and the torque arm, the tail shaft had already hole for mounting it, so no problem

still need to install kick down cable, shifter mechanism and convert it to manual speedometer drive.

If you are alone, be carful installing an engine/trans, yes - it is heavy, if the floor is uneven or on an incline, you can use an electric winch to ease it along,
- as you pushing it, will make it swing and that is not good when it is 4 feet of the ground.

Thanks from Erik