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One of the very best swaps you can ever make is replacing a TH350 or TH400 with a TH700R4. When I bought my 454" powered '71 I knew the TH400 would have to go because of the horrendous fuel mileage I would get. So after plunking down $350 at the local wrecking yard I came home with a totally worn out TH700R4 out of a 1991 van.

To tolerate the extra torque of the 454" I rebuilt the TH700R4 with performance aftermarket parts then made the swap in only one day; the total cost being around $1700 (which included the drive shaft cutting, the new tail housing with a mount pad, and heavy duty torque converter).

With the TH700R4 I can cruise at 70 mph at only 1800 rpm and get around 16 to 17 mpg; about 4 more than I would have gotten with the TH400. Fish was the first SmokinVette member to swap one in and I was the second. And since I made the swap several others have made the swap. Why run an obsolete transmission when the fantastic 30% overdrive TH700R4's exist?
 

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how much HP can a stock 700 handle?
all mine has is a shift kit (semi-manual shift kit)
never used a 100 shot with it. And dont know how much it can handle
the monster in a box is $500 and labor is $300 dont wanna spend that if a dont have too
the motor makes like 300HP
 

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is it a first generation 700r4? if so, not much, smaller input shafts...... if its a later year, it should handle a 100 shot..besides, with stock tires you probably won t get enough traction to hurt anything..if you want more, then all you need ,is to improve yours with better clutch pacs and a Fairbanks Servo, etc.
 

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is it a first generation 700r4? if so, not much, smaller input shafts...... if its a later year, it should handle a 100 shot..besides, with stock tires you probably won t get enough traction to hurt anything..if you want more, then all you need ,is to improve yours with better clutch pacs and a Fairbanks Servo, etc.
Thanks :thumbsup3:
its also a 91 and dont know if the clutch pacs are new but they have lasted 7 months (about 700 miles) driving the car like I stole it
and the oil is still fresh :woowoo:
 
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