[81 gmc]

I am finally getting around to working on my toy. I have an 81 GMC shortbox with a 350, Crane cam, Edelbrock intake and carb and Headman headers. It currently has a TH400, non-posi with 308s. I am currently installing an Eaton posi with 373s and have a T5 in a local shop being cheched out. My question is whether there are any advantages to either hydraulic or mechanical clutch linkages, for example release time. The truck will be a daily driver and eventually I want to increase the power (can't have too much of that) to the 350hp range. Also if I go to a hydraulic setup what is out there that I can use (s10 - s15, Camaro) or does it have to come from a similar truck. Lots of questions and choices but I am hoping to get some help in the decision making process here. Any input will be helpful.

Cheers

 

[packratwrecker]

Why not use a hyd setup off an 85-87 C/K? Unless you have issues with the T5, it should be a bolt in deal, more or less. Aside from the firewall not being dimpled for the clutch master, it seems pretty straight up to me.

There is always the option of using a race setup, but I'm not big on that for daily drivers.

 

[M&M CUSTOM]

You would also need the clutch pedal and associated hardware for either one, and your truck would have come from the factory with the mechanical linkage.

Gm trucks started using hydraulic clutches in 85, and all of those parts will directly fit into your truck without much hassle or any fabrication.

It would be best if you could get everything you need from a single donor truck, and many of those parts are also available new.

I have also seen kits to convert the mechanical linkage bellhousing to hydraulic.

Sorry I haven't been a deciding factor, but you know you have a choice.

 

[81 gmc]

Thanks, I have dug a pedal assembly from a mechanical setup in a 78 but the rest of the linkage was pretty worn. Is this the same pedal setup as for a mid 80s hydraulic? The dimple marking is in the floorboard of my truck so that isn't a problem.

 

[packratwrecker]

Never thought of that....

Totally different geometry at work. Some pieces may interchange, but the hyd setup pushes out, instead of down, and with much less effort.

I'd agree with M&M. A salvage yard would probably make you a bargain for pedals and hanger, if you buy the master, slave, and bellhousing.

Just not a high demand item. Masters and slaves can give trouble, but I've never seen a hanger group fail.

 

[81 gmc]

Thanks Packratwrecker and M&M,

Between the advice from the two of you I think I will look for a complete setup from a mid to late 80s, seems like the easiest thing to do and I think it should be reliable.

I just finished installing my Eaton posi and 373s tonight. A couple days of break-in and I will be interested to see what the difference is off the line.

I'll keep up to date on my parts search but it may be into the new year before I go shopping, christmas ya know.

Thanks again, have a safe holiday season and keep the rubber side down.