swapping a 700r4 for a th-400
#1
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swapping a 700r4 for a th-400
I own an 86 IROC and my 700-R4 is gone. I am wondering if it is possible to swap a TH-400 in its place. Would I need to change anything like the driveshaft, torque converter, etc??
The reason is because I currently have a th-400 and don't have the money to spend on a rebuilt 700-r4. Would it be more expensive doing modifications to the current car to do the swap?
Thanks for your help.
Chris
86 IROC
350 (to much to list)...
The reason is because I currently have a th-400 and don't have the money to spend on a rebuilt 700-r4. Would it be more expensive doing modifications to the current car to do the swap?
Thanks for your help.
Chris
86 IROC
350 (to much to list)...
#2
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i did that a while back......you'll need the Hurts Swap kit so your tranny mount will line up and it has provision for the torque arm. you'll need a new convertor and a new drive shaft.
#3
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
The driveshaft will be a lot shorter. You'll also need a TH400 slip yoke for the driveshaft since the TH400's is larger than all the other GM trannys.
Swapping in a TH350 is a lot easier.
The torque converter is a judgement call but it's best to buy a new one with a better stall speed anyway. The same torque converter will fit on TH350/TH400 and late 700R4's however the TH400 converter uses a different bolt pattern on the flexplate. An aftermarket flexplate will have the dual bolt pattern for both types.
Swapping in a TH350 is a lot easier.
The torque converter is a judgement call but it's best to buy a new one with a better stall speed anyway. The same torque converter will fit on TH350/TH400 and late 700R4's however the TH400 converter uses a different bolt pattern on the flexplate. An aftermarket flexplate will have the dual bolt pattern for both types.
#4
I think they caught everything you need to know!
BTW stephen 87 IROC - I'm just finishing up my 505 cu 85' IROC with Dart Pro-1 ported alum. heads, 1050 dom., hyd. roller, Eagle 4340 4.25" stroke crank, 4340 H-beam 6.385", JE 11:1, TH-400 full man. reverse, 9" art carr conv., ford 9", locker, 3.70 gears, strange 31 splines, but mine is a street car with 4 wheel x-drilled disc's, 17" torque trusts, 315/35r17 BFG drags, 5" harwood and a 6-point cage. I'm glad to see another 3rd gen with a BBC, when you stroke it your gonna love it!!! RPM from hell !!!!
BTW stephen 87 IROC - I'm just finishing up my 505 cu 85' IROC with Dart Pro-1 ported alum. heads, 1050 dom., hyd. roller, Eagle 4340 4.25" stroke crank, 4340 H-beam 6.385", JE 11:1, TH-400 full man. reverse, 9" art carr conv., ford 9", locker, 3.70 gears, strange 31 splines, but mine is a street car with 4 wheel x-drilled disc's, 17" torque trusts, 315/35r17 BFG drags, 5" harwood and a 6-point cage. I'm glad to see another 3rd gen with a BBC, when you stroke it your gonna love it!!! RPM from hell !!!!
#5
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
I don't need to stroke it. Going to alcohol I should be running mid 10's next year. Going bigger than 468 will mean to many changes. My heads won't flow enough and the headers are too small for a bigger engine or I'd go right to a 540.
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