10mpg

I have a 1987 IROC-Z28 305TPI with the standard 700R4 trans..

The only transmission mods are a B&M ratchet shifter..

It has had a recon exchange trans fitted by the previous owner at a large cost by a reputable garage,though this was a good few years ago, the car has been maintained meticulously and the trans serviced regularly.

When I got the car it wouldn't kickdown at all really and changed up under WOT at 2500rpm(ish) I followed the fantastic instructions on here for adjusting the kickdown cable and it now changes up at 4000rpm and it will kick down if you really nail it, but it doesnt like to do it..

Is this normal?

here's my car


Ideally i'd like it to change up at 5000 or even a little more, is this possible?

Could the ratchet shifetr be upsetting it?

Atilla the Fun

Try changing the governor for one from an L69.

10mpg

Thanks, parts like that are not that easy to come by over here, is there a part number i can use? or i might be able to find one from a car being parted out if I know what year/model to look for?

Wadebryant

The 700R4 shift points can be modified by the installation of a governer calibration kit. These two are sold by Summit Racing; 1) B&M BMM-20248 and 2) TCI TCI-326500. http://www.summitracing.com

I installed the B&M calibration kit. Had to lower the transmission to do it as access was very restricted. If it hasnt already been done, I might also suggest that you consider upgrading the servos, add a shift kit and an external trans cooler while you're into this project.

Good luck

10mpg

Thanks for that, I have found the B&M kit and it will be ordered, i was just wondering where it should shift as standard?

Atilla the Fun

No higher than 5000 until you improve the exhaust system and the cam. Even so, no higher than 5500 for as long as you keep the long-runner TPI system. If you want high-rpm power, plan on an HSR and 3.73:1 gears.