Project “Polar Bear”: 1989 V2500 Suburban

[brad2274]

Hey larry, joined the forum after flipping through your swap threads and some other members threads. looking to buy a square body suburban to build as an expedition type vehicle, but being a college student i need decent gas mileage. and since itll be in florida most of the time the ac needs to be real cold & plentiful. Do you think a 5.3l with 4l60e swap (4wd burb hopefully, but i dont need much power, no towing or heavy climbing plans, just trips and dirt roads) would get me in the 17 highway range? and you think its possible to use modern gm A/C parts like the compressor, condenser, blower, evap in a burb without too much headache? ive done some ac work and did an obd2 newer cluster & dash swap with 150+ connections in my honda using diagrams

 

[Larry]

Hey larry, joined the forum after flipping through your swap threads and some other members threads. looking to buy a square body suburban to build as an expedition type vehicle, but being a college student i need decent gas mileage. and since itll be in florida most of the time the ac needs to be real cold & plentiful. Do you think a 5.3l with 4l60e swap (4wd burb hopefully, but i dont need much power, no towing or heavy climbing plans, just trips and dirt roads) would get me in the 17 highway range? and you think its possible to use modern gm A/C parts like the compressor, condenser, blower, evap in a burb without too much headache? ive done some ac work and did an obd2 newer cluster & dash swap with 150+ connections in my honda using diagrams

Welcome! Sorry for the late reply as I was traveling this week. I know your area pretty well as my in-laws live down the road from you in Satellite Beach half a year. Yeah, a 5.3L would work well for you especially at low attitude. There are tons of write ups on 5.3L swaps that outline the options for A/C compressor mounting. You wouldn’t need to worry about the rest of the A/C system as the blower and everything else will work the same. The compressor is just a pump regardless if it is an old R4 or a late model HT6 compressor. As you are probably aware the stock A/C compressor location on a 5.3L creates interference issues with the square body passenger’s frame rail. Many people cut the frame which is a total hack way of doing it. Cutting the frame is a horrible idea. Check out 67-72chevytrucks as 5.3L swaps have been well documented there in the 73-87 section as well as LS swap section.

 

[brad2274]

Thats crazy i live in satellite beach, right next to the airforce base hahah. i listed melbourne because i thought sat beach was too specific. Cool i hope to pick up a burb in the next two weeks and start gathering parts, ive been looking for those ac brackets but havent found a good source yet.

 

[Larry]

Thats crazy i live in satellite beach, right next to the airforce base hahah. i listed melbourne because i thought sat beach was too specific. Cool i hope to pick up a burb in the next two weeks and start gathering parts, ive been looking for those ac brackets but havent found a good source yet.

Sounds like you are practically neighbors as they live right down the street from Patrick AFB off Berkeley. Here is a source for LS brackets so you don't have to hack up a frame. As you can see, LS engine install bits and pieces are not a cheap date. To do a swap right, it typically cost 2 to 3 times the amount a person paid for the actual engine just to purchase the install pieces (exhaust, wiring, cooling, accessories, etc.). Be prepared! A $500 engine can cost you an easy $2500 just to get it in and running correctly. By the time you are done a $500 engine can end up being a $3000+ engine swap when the dust settles.

 

[Larry]

Little update on the Polar Bear…. Now that work travel and vacations have passed I finally had time to run it up to a Dyno Tuner in Colorado Springs to sort out the ECM tuning to accomodate the RayLar cam. I tell ya, what a difference having a live dyno tune done by someone that knows what they’re doing makes. The big bear runs sooooo much better now. No more cam lope either! She idles smooth like a Cadillac.

The dyno results came in at 301HP/386 torque at the wheels. Not too shabby considering the original TBI 5.7L probably laid down around 110-130 HP to the ground and this shop claims most Jeeps that come through their shop rolling on 35” tires with LS engines are putting down barely 280 lb ft of torque to the ground. He also claims the 4x4 drivetrain and tire loss is around 25 to 30% so with that, I was pretty happy with 301/386 but it would be interesting to see what the flywheel HP/Torque would have been. Next project is to get busy making the A/C lines now that the weather is heating up.


For the best audio pleasure use earphones and a second set of earphones up your nose to smell the exhaust

 

[SwampStomper]

Oh sweet jesus. I saw like 3 tools laying on the ground in that time lapse. The tidiness really shows in the build. As if I didnt want an old burb bad enough.

 

[whoareu2200]

That is freaking awsome Hard work pays off. sounds amazing and good numbers. I need an 8.1

 

[justcuz]

Those are some nice numbers indeed!
It always amazes me how newer cams can run pretty high lift and fairly long duration and still idle so nicely. Obviously larger lobe separation helps a lot, but cam technology in the last 20 years has really improved.
How was your desert trip and do you plan on posting a thread for it?

 

[Larry]

Oh sweet jesus. I saw like 3 tools laying on the ground in that time lapse. The tidiness really shows in the build. As if I didnt want an old burb bad enough.

Thanks! Yeah, I am anal about keeping the work space clean and tidy. Just makes a job go more efficiently when you’re not chasing tools and what not.

That is freaking awsome Hard work pays off. sounds amazing and good numbers. I need an 8.1

Everybody needs an 8.1L! :coffeedrink:

Those are some nice numbers indeed!
It always amazes me how newer cams can run pretty high lift and fairly long duration and still idle so nicely. Obviously larger lobe separation helps a lot, but cam technology in the last 20 years has really improved.
How was your desert trip and do you plan on posting a thread for it?

And that is the beauty of this RayLar cam. It is moderately aggressive but it has large lobe separation to calm down the idle. Early on when I first installed the engine it had a few clogged up injectors from sitting and the tune was way out of whack where it loped like a race car. After the new injectors and now this dyno tune it idles just as smooth as my other two stock 8.1Ls.

Desert Trip 2015 was great! We did White Rim and Lockhart Basin into the Needles District. We spent 7 days out on the trails. Great time with great friends. Will have a thread on that when I get some time. Below is a video of Lockhart Basin to hold you over. One of my buddies also has several videos and pictures that are not uploaded yet.

 

[justcuz]

Looks like a nice trip. Looks like Lance was along for part of it with the Suburban.
Does your roof ever touch the camper? It looks close in a couple of shots. Have you ever considered adding another cross member to combat the chassis flex?
What air pressure were you running there?
Also want to run an engine build question by you, would you rather I PM you or share info with others. It is for my 73 Suburban.

 

[Larry]

Looks like a nice trip. Looks like Lance was along for part of it with the Suburban.
Does your roof ever touch the camper? It looks close in a couple of shots. Have you ever considered adding another cross member to combat the chassis flex?
What air pressure were you running there?
Also want to run an engine build question by you, would you rather I PM you or share info with others. It is for my 73 Suburban.

Yeah, Lance caught up with us for the Lockhart Basin portion of the trip after he finished up at the Overland Expo. Nope, surprisingly enough the camper does not touch the roof. That was one item I made sure Robby at Phoenix made sure of. We measured, measured again, then measured some more to make sure the two wouldn’t swap paint under hard flex. The videos make the camper look like it gets much closer to the roof than it actually does. Next time you see it, take a look at the roof and camper bottom. No touch marks exist. ….and no, I am not interested in doing anything to the frame. Frame flex is perfectly normal on these old trucks where GM engineered flex points. I’m not about to change any of that and risk the chance of causing something to break. My dad’s ’78 K20 flexed the same way from the day it rolled off the assembly line and the class 5 through class 8 trucks my company builds with C-channel frames flex like mad too. Watch a semi pull from a stop light and see the frame flex the same way. That is the way C-channel frames are. It seems people get so accustom to looking at new stiff boxed framed pickup trucks they get the idea something is wrong with the old c-channel frames when then flex. The frame flex question/comments come up constantly! LOL

These were new tires for this trip so I played with the air pressure a little bit. It worked best at 16 psi front/18 psi rear. Duratrac 315/75R16 load range E.

Shoot me over a PM and I’ll try to answer your question.

 

[smlobx]

Great video!
Maybe a little more rock climbing than I like to do but it looks like a good team with everyone healing each other out!
Maybe someday.....

 

[justcuz]

Yea my square body's all flexed too, but when I put the heavy utility body on the 1/2 ton short bed and the 3/4 ton suspension and axles I always felt another crossmember would have been benificial. Keep in mind I was building suspensions and chassis for off road race cars back then and every stock chassis cracked and broke.
I love the way you guys are running your tiltin hiltons through the trails.
Spotters are nice to help avoid driving over stuff that induces undue strain on steering and suspension.
The scenery looks fantastic!
I'll bet that trip was a welcome relief for Lance compared to the mud of the Expo.
Mud is OK but it is such a pain to clean up after, I usually set a lawn sprinkler under my vehicle for a day after a mud trip.

 

[GJStringert]

...Glad to see I'm not the only one nuts enough to take a ECLB Cummins up technical terrain haha!

Good stuff as always Larry. Good numbers on the Polar Bear!

 

[1stDeuce]

Heheheh That dyno vid has me grinning from ear to ear... Nice work!! IIRC, the tune and cam were the only mods, aside from headers... Any idea how this 8.1l might compare to a stock one?

Great... I'm now back on the lookout for a GMT800 regular cab 4x4 with an 8.1, and a 6-speed... Unfortunately, I think all the forest service trucks that were equipped that way have been sold off now, and I doubt many existed in private hands.