Collecting information for a 1967-1972 K20 Surburban 5.9 Build

[PropMan]

Hello All,

I am collecting info for a build, any and all help is appreciated.

The plan is to work out most details then collect parts and begin the build.

Known Details:

1) 1967-1972 K20 Suburban- Searching for one now!

2) 5.9 Cummins - Not sure which, been reading lots of threads. Leaning towards Gen2 12v possibly 24v with P7100. I like to stay away from the computer. Any info here is helpful.

3) I'll fab some things but want to buy the time consuming parts if possible, being self employed means loss of income when working on personal projects. List of current suppliers needed. I've found a few on the internet BUT referrals are always better than flying blind.

4) This will be a 3-5 year project!

[C20scott]

2) If you have your mind set on the cummins for a diesel swap, my opinion would be that the 12valve should be your choice over all of the newer versions. The 12v needs 2 things to start at bare minimum, fuel and a 12v source for the starter, the 24v needs a computer. If you go 12v, 100% go with the P-Pump, sounds like youve already done your research.

3) fabrication parts can be found all over the net. ORD "Offroad Design" is helpful and specific to chevy. DIY4x has a bunch of fab oriented parts and has an emphasis on chevy as well.

[rgreathouse]

A few tips from things Ive learned along the way...

Do not start mocking up motor mounts/ Trans crossmember until you have absolutely everything in place. Engine placement is a balance between #6 valve cover being too close to firewall, fan too close to radiator, intake manifold hitting master cylinder. The turbocharger gets very close to heater core and a downpipe is a very tight fit. Engine placement up and down is also a battle. Oil pan gets close to front differential if not positioned just right. It can definitely fit very nice just take your time and be sure everything is there.

Also keep your options open...
If running 4" exhaust it will be a very tight fit past the transfer case. A driver side drop transfer case and front differential would make this much easier. If a passenger side setup is a must keep this in mind during mock up.

Set goals and stick to them...
Initially I planed on a stock non Intercooled 1st gen motor with a stock turbo. These projects can take years to complete and that can lead to changing of plans and upgrades. Now I am doing a p7100 swap, intercooler, and s300 turbo. It would have been much easier to have these plans initially and build accordingly.

Lastly plan on a solid suspension. Off the shelf lift leafs will not do.

Hope this helps!

[rgreathouse]

Also be sure to follow the great build threads on here like dieselwrenchers long horn and ryanroos build!

[Dieselwrencher]

All is great info here except for the part about off the shelf lift leaves not working. I can tell you I have built 3 square body chevys with rough country and skyjacker front lift springs, and have had zero issues with them. Now, each truck already was lifted previously and had used lift springs in them so they were essentially broke in already. I haven't had any break or sag severly due to a Cummins swap. Let's take my Longhorn for instance. It has 4" rough country springs that were in my brother's V30 for years with a Cummins. He parted that truck out and I purchased them and stuck them in this truck. No sag. Tony's V-rig, 89 Burb, had a 6" Skyjacker lift previously with a 350. The Cummins has been in there for 2-3 years and I haven't heard any issues other than it settled about an inch after he first started driving it with the 5.9. He hauls a 10,000lb or heavier bumper pull dump trailer with it frequently as well. Are custom springs a good idea? Sure, if they're in your budget. But I wouldn't say that off the shelf lift springs won't work.

I'll also add that a P-pump 24v is a great option. However, the worst part of that is the conversion injection lines are pricey and like to crack. I haven't heard of any one shop that bends them that haven't had them crack. So beware of that.