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View Full Version : 700r4 vs 350 turbo trans



3dinter
01-21-2012, 08:43 AM
350 turbo with 2.52 x 2.56 = 645
350 turbo with 2.75 first gear x 2.41 = 662
350 turbo with 2.52 x 2.73 = 687
700r4 with 3.06 x 2.29 = 700
350 turbo with 2.75 first gear x 2.56 = 704
700r4 with 3.06 x 2.41 = 737
700r4 with 3.06 x 2.56 = 783
This is in first gear only, with a 450 cam rule, stock heads/srings with 1.94 & 1.50, stock gm cast iron intake, 4v relief piston, stock cast exhaust, 4412 Holley on a 3000 lb dirt car w/Hossier slicks on 3/8 to 1/4 mile semi banked tracks in Central Texas.
last year we ran a 350 w / 2.41, 2.56 & 2.73 rear gear and got about 5900 to 6700 rpm, depending on what intake we used. "Quad Stock cast, Stock Cast marine and Stock Cast Z-28 high rise"
WHICH WOULD BE THE BETTER TRANS AND WHY ??

fast_crew
01-22-2012, 08:22 AM
If those 4v relief pistons are hyeruetectic or cast, try to limit the rpm's to about 6-6200. If forged don't worry about it. On those short tracks if you can hook it up go for the more gear to get it up out the hole, The 350 trans should weigh less and have less rotating weight then the 700. Gear is hard to say, which intake due you plan on running, 700 rpms is a pretty big sweep with an intake swap, where there other variables? Different track altogether I suppose? You will probably be better off swapping rears (gears) for different tracks to keep in your rpm range.

3dinter
01-23-2012, 11:51 AM
If those 4v relief pistons are hyeruetectic or cast, try to limit the rpm's to about 6-6200. If forged don't worry about it. On those short tracks if you can hook it up go for the more gear to get it up out the hole, The 350 trans should weigh less and have less rotating weight then the 700. Gear is hard to say, which intake due you plan on running, 700 rpms is a pretty big sweep with an intake swap, where there other variables? Different track altogether I suppose? You will probably be better off swapping rears (gears) for different tracks to keep in your rpm range.

We got the most RPM's with the GM performance Cast iron Z-28 high rise. yes one track was a lil shorter on the straights and the other was more circular. Yeah after looking it over your prob right more easier to swap gears for each track.