Posted June 9, 200420 yr comment_84566 Hello everyone. I have a 1970 240Z with a 2.8 (f54), a p79 head and an 82 r-200 dif. My question is, do I use the 1978 or 1982 5-speed I have sitting in my garage. The 78 may be better off the line, but I may get better mpg with the 82. By the way, I have already cut the hole in the trans tunnel for the 78. Let me know. Thanks, Rick. Link to comment https://www.classiczcars.com/forums/topic/12132-78-or-82-5-speed/ Share on other sites More sharing options...
June 9, 200420 yr comment_84577 It's just a matter of prefference. Lower 1st gear or higher 5th gear. I have a 82 trans in my 78 and it requires no modification which is to say the the hole you cut in your 70 would work for both of them. Unless the ZX trans is a T5. Link to comment https://www.classiczcars.com/forums/topic/12132-78-or-82-5-speed/#findComment-84577 Share on other sites More sharing options...
June 9, 200420 yr comment_84580 Rick, I'm ALMOST certain that the 70~71 shift hole mod would be the same for both transmissions.#1 priority - Which trans do you have the most confidence in as far as condition? Link to comment https://www.classiczcars.com/forums/topic/12132-78-or-82-5-speed/#findComment-84580 Share on other sites More sharing options...
June 10, 200420 yr Author comment_84684 Both trannys are in great shape. For everyday driving, I want to choose the one with better off the line performance. Let me know. Thanks. Rick. Link to comment https://www.classiczcars.com/forums/topic/12132-78-or-82-5-speed/#findComment-84684 Share on other sites More sharing options...
June 11, 200420 yr comment_84701 The ratios are as follows:78 (FS5W71B) 1st-3.321, 2nd-2.077, 3rd-1.308, 4th-1.000, 5th-0.864.82 (FS5W71B) 1st-3.321, 2nd-2.044, 3rd-1.408, 4th-1.000, 5th-0.752. Off the line performance would be about the same though 2nd in the late trans is slightly higher, and third is lower. I really don't notice much difference in second and my car pulls slightly better in third than the stock trans but that fifth gear drops the engine down to a nice low cruising rpm on the freeway and does yield better gas mileage. And added plus is that my stock trans was cast iron and the late trans is aluminum. Anything that saves weight on a 280 is a good thing! Link to comment https://www.classiczcars.com/forums/topic/12132-78-or-82-5-speed/#findComment-84701 Share on other sites More sharing options...
June 16, 200420 yr comment_85410 I recently changed the tranny in my 75-280 from4 spd to a 78 5-spd. Although the 5th gear is "better" than the old 1:1 ,I had expected a lower RPM for Highway cruzin. Its3K RPM at 70MPH +/- (3.54 R200 ) . So since both 1st gears are same ratio, I'd suggest the82 Tranny !! Link to comment https://www.classiczcars.com/forums/topic/12132-78-or-82-5-speed/#findComment-85410 Share on other sites More sharing options...
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