The Stovebolt Site Forums The Shop Area Engine Shop hydraulic throwout bearing

I've got a Howe TOB on my t-5 behind a 261. No reason you couldn't do the same thing with a sm-420 and a 235. However, it would be easier to repair 3-5 years down the road when the TOB fails if you used a standard TOB and slave cylinder. The larger truck belhousings came set up for that. If you've got the stock sm-420 and closed driveline, by the time the hydraulic TOB fails you'll be ready to upgrade to a t-5 or it'll be time to change the clutch plate.

Instead of using a Howe TOB from speedway or whatever, you might consider using the Jeep Cherokee hydrulic TOBs- They cost around $70 from autozone. Then you'd need a mastercylinder and someway to mount it. I mounted mine next to the brake booster and hooked it up to the original pedal. Next time I do it, I'll use the jeep TOB/MC if the id of the TOB is the same as the OC of the tranny input shaft housing.

I understand your problem though, the reason I went with the hydraulic TOB is that with a power brake booster in the stock M/C location you can't use the mechanical linkage.

Have you considered hydrovac brakes rather than the booster/m-c set up? The larger trucks came with power brakes that used a hydrovac unit bolted to the frame under the passanger side of the cab so it wouldn't interfer with the clutch linkage.