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View Full Version : 700R4 shift kit recommendation



rwd_pete
05-18-2015, 08:33 PM
Currently I have a THM 350 with a B&M shift kit behind my carbed/HotCam 95 Vette LT1. Rear gears are 3.08 open in a 9" and the car ran 14.1@99.7 in my 56 Ford and barks the tires in second gear. I have a 3.70 posi for the car this year and plan to install a 700R4 that I have. My son got me a 2400 stall B&M convertor for it.

Originally I installed the '86 Caprice 700r4 trans behind a 400 sbc in another car. It had a soft shift and I installed the same type $45 B&M shift kit as in the THM 350. I only installed the kit in the RV/towing mode. I didn't want the bobble head effect when it shifted in this car. However, I was never happy with the shifts. For street/strip mode I think there was one more spacer to increase spring pressure in a circuit. For this new application behind the LT1 I would like to firm up the shift. I don't want to smoke the transmission.

I could buy another B&M kit and install the street/strip missing component/components. Or I could buy another brand shift kit or ? Any suggest to firm up the shift would be appreciated.

popo8
05-18-2015, 09:56 PM
Cahall

CPT
05-19-2015, 11:18 AM
You don't need to buy any shift kit to firm up the shifts in a 700R4. You can use a spare 4th accumulator piston and a flat washer to block the O/D accumulator. You can drill and tap the feed hole in the 2nd accumulator feed and install a set screw. you can leave out the 2nd gear check ball. Install a "Corvette" 2nd servo, put a .500" boost valve in it, and drill a couple holes in the plate. Low TV cable settings will also cause soft shifts.

gmpowered
05-19-2015, 02:05 PM
B&m kits generally suck. No offense.

You need to look at what sonnax has. They actually engineer r&d their fixes and upgrades.