87 Crew Cab 454/TH400 to Cummins/NV4500

[jltait]

Hi all been lurker on this site for awhile but this is my first ever build thread, on this or any site for that matter. I have had quite a few projects, but never really documented them well in the past. I will try to lay out as many details as I can as I move forward with this project. I have been hit and miss with pictures but I will put all into this thread. I struggled to find some of the details of this conversion so I will put as many as possible in this thread to aid others who are doing or plan on doing this or a similar conversion.
The reasons for the conversion is first for mileage, I have had diesels in the past and wanted to get better fuel economy. Secondly the 454 had a couple issues that needed to be rectified, namely a bad rear main or seemingly rear main oil leak and a cracked (nearly in half) exhaust manifold. Considering I had the Cummins engine hanging around in my garage for some time now and a 454 with the issue outlined making this conversion happen just made sense to me.
Jason

The truck

[y5mgisi]

Well hop to it! Love to see it done! Nice looking truck btw.

[STOCKISH]

Definately looking forward to it!

[jltait]

First up was converting the truck from auto transmission brake pedal and bracket over to manual transmission pedals and bracket. I fully expected this part of the project to go very smooth and quick, however I ran into some hurdles that I will outline. I now believe the pedals and bracket were from a non hydroboost truck and mine has hydroboost. The brake pedal that came with the manual parts I bought had the stud for the pedal to master cylinder push rod in a lower location SEE PICTURE(gray primer is the purchased pedal The natural/black pedal is my original). Therefore I had to modify the original brake pedal to use with the manual setup. I did this by cutting the foot pad piece off, cutting it down, then re-welding it to the main upright. The 2nd and 3rd photos show the completed work. In the photo where the gray primer is not evident the upper pedal is my reworked original.

This took care of the brake pedal....now onto the hanger bracket.

[jltait]

The next hurdle I ran into,which I again attribute to hydroboost vs. non hydroboost, was the main pedal hanger bracket. This bracket is mounted with (4) studs through the firewall and (2) through the dash. My original bracket had (2) of the firwall studs (lowers) welded to the pedal bracket and protrude through the firewall with nuts bolting onto them in the engine compartment, the other (2) studs are welded to the hyroboost master cylinder bracket and protrude throught the firewall with nuts bolting onto them on the passenger compartment side of the firewall. The manual transmission pedal bracket I bought had all (4) stud welded to it and the nuts bolting onto them in the engine compartment. In the attached pics outlying this issue the gray primer bracket is my orginal pedal bracket and the rusty looking one is the manual transmission bracket I bought, It would normally have the clutch pedal bracket spot welded to it as well but I have already removed it in this picture in preparation for transferring it to my original pedal bracket. I could also have transferred the studs but my bracket was a whole lot cleaner as well.

Jason

[jltait]

I remedied the issue with the pedal bracket by removing all the needed parts from the manual bracket I procured and moving them to my original pedal bracket. The parts required to be move for this change included the clutch pedal hanger bracket and clutch pedal interlock switch bracket. These are additional pieces spot welded to the same main bracket. I drilled the spot weld and welded them to my original pedal bracket. Again my original has gray primer on it in the picture and the manual bracket procured for this project is rusty in the reference attachment pictures. The last picture I circle the interlock switch bracket. The first picture is the clutch pedal bracket (Top view)removed from the manual transmission main pedal bracket and is prepped and ready to be welded to my original main pedal bracket. Unfortunately I do not have a good picture of the completed unit but the last two pictures do show the clutch/main pedal brackets after I welded them together. 2nd picture is a top view of the assembly and the last picture (with circle)is looking at the assembly viewing it from the left side looking at the clutch pedal broadside.
JLT
Thanks for the comments guys.

to be continued...

[jltait]

Next up was mounting the Master cylinder, I am using a stock square bode MC made by Sachs. Here you can see the mounting holes and clearanc holes for the MC body that I made. The upper mounting hole is obscured by wiring, but if you look closely you can see it where the yellow and green wires are intersecting.

[jltait]

Once the clutch master cylinder and pedal kit were installed I could move the truck out of the workshop and move on to prepping the engine and Transmission. I knew the Cummins rear main was leaking as this showed up while I had it running briefly on my test stand. I replaced the rear main with a Fel-Pro part that was inscribed made in the USA. Here are pictures of rear main replacement. The aluminum seal housing does not need to be removed for the seal replacement but if you do remove it the pan seal will be broken and you may need a new pan gasket at that point. I left the seal housing in place. I used two self tapping machine screws, screwed them into the seal 180* apart and pulled the seal with a wrecking bar supported by a piece of wood. Mine actually almost fell out, the seal had actually spun in the aluminum housing, nut sure what would cause this. First picture is after the old seal was removed and the second is with the new fel pro seal installe. The (This)seal kit comes with driver that is use to drive the seal into place and also has a lip to prevent driving it in to far.

[Mattman2010]

Jason, Good to see you finally have a build thread going, even though the build is almost done! Cant wait to see more pictures of your progress!

Matt

[Mattman2010]

Last PM I got from him he said that he is going to be out of town a lot in the next week or two and some things have came up so the project is on the back burner for right now.

He did however drive it down his driveway. He has a few things to button up, this build thread is pretty far behind where he really is.

[STOCKISH]

Cool, cant wait to see pics!

[jltait]

Yeah, I made some progress but only had 6 hours or so worth of it. I will give an update soon. I am so tired right now I can hardly keep my eyes open.
Jason

[jltait]

Okay, things went way weird but I should have an update soon. My hard drive crashed and I thought all was lost concerning pictures. Fortunately I was able to resurrect the drive well enough to pull most of my pictures from it.
I have also been working to get my Dad's house/garage/barn cleaned out to put on the market. He is disabled and live in an assisted living facility. Needless to say I have had some roller coaster luck lately, hower I have made progress on the truck and actually drove it 130 miles or so this past weekend.
I will try and get a good solid update in this week.
JLT

[my4by2]

Sweet build man! When I started my project I originally wanted to use a 4BT Cummins, but eventually ended up going with a 6.0L gasser. Look forward to more pics soon!

[STOCKISH]

Still looking forward to pics buddy!

[jltait]

Well, after having to resurrect my hard-drive to get 'em back I am just gonna start dumping them in here with brief explanations, then add detail by editing after the fact
JLT

[jltait]

Then I started to test fit the Cummins.

[jltait]

About this time I confirmed an issue I previously suspected. Since this was an automatic 2wd truck Cab the manual transmission was not going to fit without either a raised transmission hump in the cab or body lift. I opted for a 2" body lift which gave me the amount of room I needed. Since I am so stubborn I opted to fabricate it, I picked up a stick of 3 1/2" diameter UHMW (Ultra-high-molecular-weight polyethylene) and had it cut into 2" biscuits. I then drilled them on a drill press and allocated the correct hardware. I had about $75 dollars in the body lift. I like that my biscuits are 3 1/2" in diameter, the ones in the kits are usually 2" or so. Afterward I did find that Performance Accessories make individual 3" pucks, this may have been a good option as it took me a lot of time to do fabricate. I do not have pictures of the body lift install at this time but I certainly could put it up on the lift and snap a few when I get a chance if someone is interested.

[jltait]

I then dug into the transmission looking for any apparent problems. And removing the GM only parts that would not be reused. More on this later.

[jltait]

More transmission pictures, including the parts that need to be swapped to convert the GM NV4500 ('96 up) to work with the cummins. I will add details about the conversion later.

[jltait]

Then It was time for the 454 to come out. Notice in the first picture the cracked exhaust manifold. Also note the amount of oil around the bellhousing, the rear main leaked bad, strangely when driven, especially at freeway speed it would somewhat seal up. This is the original engine with only 80k miles so that is probably the issue with the seal leak. It was not driven much but towed heavy.

[suxtobu65]

Any updates sir?

[spgill2000]

What happened to this project?! Did it get finished?
Posted via Mobile Device

[spgill2000]

Hello? Project fail...

[Bowtie_luvr]

No project was not a fail. I had issues with my id/pwd here, family issues with my Dad's health and it came down to crunch time. I needed the truck, so I finished it (functional, never really finished) without any updated here. I was never able to get my profile here functional again, so I opened a new profile. I have several thousand miles on her now since the conversion. Injector lines have been the only reliability issue, I replaced them all with new Cummins lines shortly after the conversion and all has been well since. I am currently adding a Western Unimount plow.