Frame Z & Trans tunnel question

[timeless_kris]

Hey fellow members, I've been lurking on the forum for a while now trying to gather as much info as I can on bagging my '81 swb stepside. I've come to the conclusion that I'm going to do a 1.5"z along with roughly a 1" crossmember pancake. I was wondering if anyone can confirm if you need to raise your trans tunnel/Install a 4wd trans hump for a 1.5"z (trans is 4l60e), I've seen a few threads touch base on this subject but no definitive answers. Any input would be appreciated. Hoping to get started this weekend, if anyone has any helpful info on z'ing in general feel free to share.

[tinydb84]

How low are you looking to go? Any reason you want to do 1.5'' of each? 1.5'' (ish) should get your about flat when you lay out. I believe justpball did a combo similar to what you are thinking on his burb and didn't have to cut the tunnel.

I went pretty extreme on my Z (due to the SFBD) and then lowered my engine to decrease the amount I had to mess with the floor.

Check out this thread: http://c10forum.com/forum/showthread.php?t=4195

A few guys have lowered the engine to avoid the trans tunnel issues. If my brother ever gets his truck back I will probably Z it 1.75'', lower the engine 1'', and call it a day.

[timeless_kris]

I was debating whether I wanted to do the full 1.5" crossmember chop or not, I don't want to hog out too much of my frame for the steering, especially with the Z, I May do it and box the frame from the front horns to where my steering notch would be for added strength. I'll have to double check but I think with a sectioned crossmember, even if I go with an f-body oil pan (engine is 5.3) it doesn't give me much space to lower the engine but I'll definitely check the clearance and give it some thought once I have the engine in place for a mock up. The truck is going to be a daily driver and I don't have money for a dropmember otherwise I would go that route, but I would like it to be as practical as possible for my budget. I've given SFBD a lot of thought too as I plan on bringing the stepsides down so they sit level with the rockers and it would be nice to have the whole thing laying on the ground, but it seems like quite a bit of work and I keep telling myself I will be happy "just laying frame" lol.

[tinydb84]

I assumed that you had a SBC. I also have a 5.3 with an F body pan. I was able to lower it 2.5 inches after I notched the crossmember. Here is a pic of it. I ended changing out the motor mounts for some bolt in ones I made.

The centerlink becomes an issue and you need to recess the engine about 3 inches to have the centerlink land right between the pan and the balancer. Then packaging the exhaust gets tough as you land right between the frame rails where the exhaust needs to be.

With the 1.5 inch sectioned crossmember you will not really have to worry about the frame. The LCA is what will hit first. You wont need to lower the engine with this method though. Assuming you have the fab skills to do a Z or crossmember section, why not do the 1.5'' crossmember section and fab up some mounts for a rack and pinion? No tunnel issues, no bumpsteer issues, no lowering the engine, etc.

[timeless_kris]

Thanks a lot for the info David, I honestly haven't thought about R&P steering as I've always either associated it with the drop member or too expensive to justify by itself but I've never thought about mounting it myself. That and I haven't mentioned one of the first things I've bought for the truck are MMW dodger series arms, again only because I hadn't even considered the rack & pinion set up and thought it would be a good alternative to clearing the steering shaft as well as not having to use my super crusty stock control arms or buy a pair just to hack up. This is going to be my first ever frame z so it's hard to say whether I have the "fab skills" or not yet but I feel confident that I should be able to build it sturdy enough. I will have someone helping me out in case I run into any issues fab-wise. Based on what you've told me I might be a little more aggressive with the frame z and bring the engine down some.

[tinydb84]

I've done a Z and a sectioned crossmember. The crossmember is really easy to do. Any reason you are concerned with the trans tunnel? That was probably the easiest part of my Z.