Any Differences between 95 GMC suburban sle 6.5 TD & 99 tahoe 6.5 TD

[Will L.]

Enhanced? As in Optimizer?

 

[FellowTraveler]

Enhanced? As in Optimizer?

It is the in-between block looks and measures exactly like the Optimizer 6500 thick casting and has small oil cooling jets however no endless highway logo and some have claimed it is cast of poorer quality materials than the Optimizer but haven't provided proof of that claim.

Some re-builders will not rebuild 6.5 blocks manufactured before MAY 99 and the number of failures of the 6.5 dropped after MAY 99 too.

If I remember right GM had sold the rights to the 6.5 td to AM General in 99 and it is not clear as to when or who cast the enhanced blocks (506) that found their way into MAY 99 and newer in GM products and it's not clear when NAVISTAR started their casting production of what is called the Optimizer 6500 but I'm thinking they claim 2000 but the enhanced MAY 99 and newer blocks appear to be cast from same molds aside the logo and all internals are the same as the Optimizer 6500.

AMG had many failures of the old stock pre MAY 99 6.5's they got from GM and installed in the H1.

 

[ak diesel driver]

Leo I was just rereading DZZ71 141 rebuild thread. I guess I don't understand why he called it a 141 block, it has 2 rows of dots that look like maybe the 4 would be missing but the rest of the of the numbers state it's a 506 block. After reading some of his other posts I got the impression it was a Ted's motor.

 

[aLpHaSuRf]

Are all 95 diesel suburbans 2500 8 lugs or where there any 1500 6 lugs. I'm going to buy one tomorrow and by the looks of aftermarket rims they look like 6 lug rims. Also it's one owner 245,000 miles no accidents according to car fax, which might not be true but looks to be mint condition. How much should I pay for her they want $6000.00

 

[NVW]

To the best of my knowledge they also came with 6 lugs. Someone more knowledgeable will confirm.

 

[aLpHaSuRf]

Okay after doing more research found that in 95 they had 2500 light duty diesel and 2500 heavy duty diesels.
LD (Light Duty) is 7200# GVWR, and semi-floater 6 lug r/e. Also equipped with the same smog as the 1/2 tons in most states.

HD (Heavy Duty) is 8600# GVWR, and full floater 8 lug r/e.

 

[Big T]

Are all 95 diesel suburbans 2500 8 lugs or where there any 1500 6 lugs. I'm going to buy one tomorrow and by the looks of aftermarket rims they look like 6 lug rims. Also it's one owner 245,000 miles no accidents according to car fax, which might not be true but looks to be mint condition. How much should I pay for her they want $6000.00

Pay no more than $5k. If there's rust, then $3K or less. I would pass if it's 6 lug.

 

[aLpHaSuRf]

I think it's 6 lug and please before I drive 5.5 hours one way why would you pass on the 6 lug?

 

[Big T]

I think it's 6 lug and please before I drive 5.5 hours one way why would you pass on the 6 lug?

6 lug would not meet my towing needs, which why I want the diesel. If you're looking for a 1/2 ton grocery hauler, then I'd look at the next era GMT-800 Suburban with a gas engine. You can find equivalent deals and you get much better brakes. Plus you'd avoid about $2,500 worth of mods that need to be done in order for that '95 to perform worth a darn.

 

[JayTheCPA]

I think it's 6 lug and please before I drive 5.5 hours one way why would you pass on the 6 lug?

6 lug is basically a 1/2 ton suspension. Not a big deal unless you plan to tow or abuse it by doing something like mudding or plowing. Unless I am missing something, you can upgrade the suspension and axles if you really want to. So aside from the suspension and axle, the rest of the powertrain is the same whether 1/2 ton or 3/4 ton. If the Burb is for a fun family hauler / highway cruiser, a 1/2 ton suspension will work (although you might want to beef the rear with an Active Suspension).

The burb does not have an EGR while the Tahoe will. Check your VIN #, the 8th letter in the Burb will be a "F", the Tahoe a "S"

IIRC, the EGR stopped in 98, so the Ho should not have it. As mentioned, check the VIN.


Here are some other basic differences from MY95 to MY99 and Ho to Burb:

> the MY99 should have dual airbags where IIRC the MY95 at best will only have driver's airbag (if it has one).

> the Ho has a weaker rear. Burb's usually had the truck strength rear, but will need to look at the diff to confirm (or get the RPO codes).

> the Burb will most likely need brake upgrades (proportioning valve per TSB, upgraded rear cylinder) otherwise you will continually accept squishy brakes and manage rear wheel locks at low speeds (when they shoes get moist). Tell-tale sign that the PO(s) never did the TSB is that the front pads show wear as opposed to the rear shoes looking like they are new (and chances are they are in fact original). Short version is that the Burbs put too much brake force on the front rotors and not near enough on the rear drums.


In terms of the minor differences in blocks, honestly I would not stress over it. Just do oil analysis and plan for replacement to a Navistar motor when the analysis shows that you have a soon-to-die motor. This could happen today, or 200K miles from now . . .

And for all 6.5's, injection health is high on the maintenance list as the average owner pays no attention to service life. If there is no history of injection pump (aka: IP) or injector replacement, this needs to happen very soon as they have 100K mile service lives; past that and you are gambling whether a hole gets burnt in the piston or cylinder wall from spraying fuel versus atomizing fuel.

While on the topic of the IP and injectors, stock-up on lube to compensate for ULSD as the current diesel is too dry for that generation injection system.

 

[FellowTraveler]

6 lug is basically a 1/2 ton suspension. Not a big deal unless you plan to tow or abuse it by doing something like mudding or plowing. Unless I am missing something, you can upgrade the suspension and axles if you really want to. So aside from the suspension and axle, the rest of the powertrain is the same whether 1/2 ton or 3/4 ton. If the Burb is for a fun family hauler / highway cruiser, a 1/2 ton suspension will work (although you might want to beef the rear with an Active Suspension).

IIRC, the EGR stopped in 98, so the Ho should not have it. As mentioned, check the VIN.


Here are some other basic differences from MY95 to MY99 and Ho to Burb:

> the MY99 should have dual airbags where IIRC the MY95 at best will only have driver's airbag (if it has one).

> the Ho has a weaker rear. Burb's usually had the truck strength rear, but will need to look at the diff to confirm (or get the RPO codes).

> the Burb will most likely need brake upgrades (proportioning valve per TSB, upgraded rear cylinder) otherwise you will continually accept squishy brakes and manage rear wheel locks at low speeds (when they shoes get moist). Tell-tale sign that the PO(s) never did the TSB is that the front pads show wear as opposed to the rear shoes looking like they are new (and chances are they are in fact original). Short version is that the Burbs put too much brake force on the front rotors and not near enough on the rear drums.


In terms of the minor differences in blocks, honestly I would not stress over it. Just do oil analysis and plan for replacement to a Navistar motor when the analysis shows that you have a soon-to-die motor. This could happen today, or 200K miles from now . . .

And for all 6.5's, injection health is high on the maintenance list as the average owner pays no attention to service life. If there is no history of injection pump (aka: IP) or injector replacement, this needs to happen very soon as they have 100K mile service lives; past that and you are gambling whether a hole gets burnt in the piston or cylinder wall from spraying fuel versus atomizing fuel.

While on the topic of the IP and injectors, stock-up on lube to compensate for ULSD as the current diesel is too dry for that generation injection system.

Excellent

 

[tanman_2006]

Never seen a factory 6 lug 6.5 Burb. They have 1500 8 lug and 2500 8 lug.

I doubt the burb is in any better shape mechanically than your hoe. Its just 6.5l life, they are rarely even 100% maintained but it's not hard to straighten them out usually.

I remember your how now and I think before spdgofast it belonged to a guy that went by VegTech or something of the sort.

 

[JayTheCPA]

Never seen a factory 6 lug 6.5 Burb.

I have seen a few on Craigslist around here. Also have seen 1500's with the 8 lug.

IIRC, at one point the 1500 Burbs also had 3.42 rears as an option.

 

[tanman_2006]

Yup, most 1500's had an 8 lug semi floater with 3.42's

I'd like to check out a 6 lug 6.5 burb. GM had so many parts combos its crazy!