z bar ?

[bsteele]

I replaced the 307 with a 350 in my '69 c-10. I kept the three speed. The z bar mount for the 307 has two bolt holes that match the 307 block. The 350 only has the back hole. What do I need to do to mount my z bar?

[70cst]

I moved this to the Engine & Drivetrain area where you should get a response to your question...

[crazy longhorn]

If you have the front "boss", you can drill & tap it (1/2" 13 NC thread). You have to be carefull not to go too deep tho...you will hit water crazyL

[Tx Firefighter]

The blank pad should be on the block where the second bolt goes. Drill and tap it for 3/8 bolt like the other hole. I've done this a few times and cast iron drills and taps extremely easy. It's not a big thing to get worried about. Just put a piece of masking tape around the drill bit to act as a guide on how deep to drill the hole. Then use a normal tap.

[crazy longhorn]

Originally Posted by Tx Firefighter

The blank pad should be on the block where the second bolt goes. Drill and tap it for 3/8 bolt like the other hole. I've done this a few times and cast iron drills and taps extremely easy. It's not a big thing to get worried about. Just put a piece of masking tape around the drill bit to act as a guide on how deep to drill the hole. Then use a normal tap.

TX, thats a 1/2" NC coarse bolt in those 2 holes to mount the bracket....crazyL

[adametree]

I just did this on my c10. I installed a 305. the only hole was the one above the oil filter. I unscrewed the ball from the bracket on the z-bar. ( so i only need 1 hole). it screwed right in to the hole above the oil filter. I then had to move z-bar bracket down the frame about 6 inches and make z-barr a little longer. so it will reach the clutch rod that is connected to the pedal.

[bsteele]

Have you tested this and does it work properly(moving the z bar)? I just hate to drill into the block. You just don't know my luck.

[crazy longhorn]

I have moved the linkage, as adamtree suggested, many times, & never had any issues....but it does require a little welding /fab work IMHO, if you are mounted in factory sb V8 spot, I would drill the hole & tap it. If you have access to a welder & can weld ,or have a bud that welds, you can move & modify that linkage(you should see mine!) Its slid back 3 1/2" , has the top arm cut off & a different arm welded on, straight shot from the peddle to the bell crank(yup redrilled the hole in the fire wall), & rodends on the pivots, both top and bottom. Does it work?....I can pull a shift @ 6800 crazyL

[bsteele]

I have the welder and feel more comfortable modifying the z bar than drilling the block. If I mess up the z bar just get another. If I mess up the block just get another one and pay someone to build the engine. Think I will modify the z bar. Thanks guys.

[crazy longhorn]

Originally Posted by bsteele

I have the welder and feel more comfortable modifying the z bar than drilling the block. If I mess up the z bar just get another. If I mess up the block just get another one and pay someone to build the engine. Think I will modify the z bar. Thanks guys.

You wont mess up the block....Im not lazy, but i tend to take the easy route(i would drill it) i would bolt the bracket up on the rear hole, snug er up, & use the front hole for a pilot. Hit it with a 1/2 " bit to give you "centerpoint". When you have the center, toss that 1/2" bit back in the tool box, you wont need it again. You only need about 1/2 " deep threads , start with a a 1/4 bit(tape it like TX said), then go 3/8(same deal with the tape). Off the top of my head Im not sure on the final drill for the 1/2" thread, but 7/16 is close(I read the drill # on the tap I am using....partimerz) I do know for a fact that you need a 1/2" 13 NC tap to do the threads. If you were close to my zip code, crap I would drill & tap it for you (NC) crazyl

[bsteele]

Thanks crazy. How far is South Carolina from you? jk I might just drill and tap it.

[Tx Firefighter]

What's to mess up when drilling it ?

Bolt the bracket in place with the one bolt so you can see where the other is supposed to be. Then step drill it up to size using the masking tape on your drill bits to guide your depth. Then tap it and you're done.

Really, think about it, what's to mess up ? Cast iron taps like butter. It's not like the block is going to crack or something. GM just quit tapping the hole when it was no longer needed for modern applications. Heck, even if you drilled it way, way too deep and went into the water jacket, just put sealer on the bolt and call it good. Your engine is full of holes tapped through into the water jackets from the factory like head bolts, water pump bolts, and intake manifold bolts. Don't sweat it.

[adametree]

yea, i was in the same boat you were about drilling it. I have just never done it. probably not a big deal though. if i knew how i would of done that. moving the zbar, doing the fab work was defintly more work than just drilling two holes

but to awnser your question it works great. You have to weld an extension on the zbar so it will reach the clutch rod. Weld it correct too; there is a lot of force being exerted on the z bar. I had to measure the hole in the new engine with the hole on the old engine and compare measurements to see how far to move back z-bar. just measure twice and cut once though.