87-91 Suburban TH400 swap to SM465/NV4500?

[93FatBottom]

Whats happenin' guys! Im in the market for a 87-91 Suburban at the moment, Looking for an 8 Lugger, with a 350, 454, or 6.2, and I had been in search for one with an SM465 trans. After 3 months I've only found ONE, an 88 GMC Suburban 454/SM465/NP208, bad synchro's in 3rd gear, but its a bare bones no power anything suburban, and the woman refused to smog it, and was firm at 2500 So I have recently found a number a smokin' hot deals on suburbans- with Auto trannys. After a few weeks of googling, I've seen posts talking about push outs in the floor board of the auto trucks that show you RIGHT where to cut to convert it to a Manual. Previously I was under the impression that the floorboards (trans tunnels) were different Automatic to Manual, so I'm a bit confused by this. I'm hoping someone around these parts might have some information I need, or maybe if I'm lucky, Pictures Im sure I can come across the clutch pedal assembly, and as for the slave cylinder, Im curious as to how to mount that and the Master, cutting holes in the firewall? I've always done manual to automatic swaps, This will be my first attempt of an Auto to manual trans. I have hopes in the near-off future to convert to a 12 valve in my future burban, since my Duallys only 2 wheel drive, and not set up otherwise for how I want to install my cummins. I have PLENTY of time to work on this project coming up, as I'm in the beginnings of a DUI court battle But it gives me plenty of reasons to save money on bars and food and entertainment, and spend money on parts/goodies for my project So, if anyone here could be so kind to oblige me, I would greatly appreciate it. Thanks guys!

 

[nvrenuf]

I don't have all your answers but I can say the push outs are there and quite convenient. I have a 91 K5 (original auto) and the floor had the pattern for the shifter hole and dimples for the boot screw locations. The firewall was the same, dimples to locate both the master cylinder hole center and the mounting bolts.

I did change out the bracket that the brake/clutch pedal hangs from inside the dash. I didn't compare them to see if they were the same as I had a complete assembly to swap in and that area was just too tight and busy to waste a bunch of time trying to see if the existing bracket would accept the clutch pedal.

As for the tunnel itself, I know they are different on older trucks for 2wd vs 4wd. I have found that a lot of stuff (like the locater dimples) became "common" on most trucks after '85. My money would bet the tunnel is the same after '85 for ease of assembly at the plants. Also, on older 4wd trucks the tunnel was removable but I've worked on 5 '81+ trucks that all have the panel epoxyed in.

 

[sweetk30]

and the 465 4 speed shifter hole is the comon factory setup. and if you swap in a nv4500 the shifter tower location moves back around 5" if i recall. so dont cut the hole till your 100% sure or patch panel work will be needed.