I need to choose between a 6.2 NA and a 6.5 goodwrench with Banks turbo kit to install in my "new" 85 Suburban K2500 (had diesel engine that was removed for a gasser swap, project was abandoned and I am replacing the diesel). I know the 6.2 is good, from my C20 which got wrecked. The 6.5 is an unkown from a quy who replaced the heads due to an overheat problem, good mechanic and he said the pistons/cylinders looked like new, engine has less than 30k.

I intend to use 90% city/freeway commuting, 10% weekend trips to Sierras, don't know what the Suburban would be like with the 6.2 NA, I ran the C20 pickup with 6.2NA and it was fine for me, but am worried about the extra weight of the Suburban being too much.

If you had your choice and cost of purchasing engine was not an issue,
which would you choose? Will the NA engine have the power for mountains pulling a 3-4000# trailer? Which one would you be more comforable with holding up under most reasonable operating conditions? Thanks for any ideas..

What gearing does the suburban have? I think you will be heading toward the 6.5l.

6.2 reliable with a 0-60 time of around 30 seconds from what some have posted. 6.5 more power available, and reliable if you keep them ponies in check.

Burban has 4.10 gearing, 700r4 (supposedly fresh-no receipts) The only reason I was leaning toward the 6.2 is that I know it has been trouble-free. The 6.5 was Overheated bad enough to trash the heads, not sure what effect that might have on the block. the guy who replaced the heads is a real decent mechanic w/o any diesel experience but he had a machinist set up the heads and he followed the Haynes manual to do the R+R. Anybody do a head job and have poor results? is there anything I can do to check the engine short of tearing it down?

Thanks for the inputs. I know these are tough questions to answer, just trying to get some sense that I am taking the most sensible approach here.

whats the year of the 6.5 ? If it is an electronic one does all the computer stuff come with it?

I have learned not to take other people word for certain things. I would go with the 6.2 for 2 reasons. 1. You know the history of the engine and know its good. 2. You are probably getting a stronger block than the 6.5 depending on the year of the 6.5. Plus, you can always turbo the 6.2 to make it very close to a 6.5.....your only giving up roughly 20 cubes. But, thats just my 22cents.

The 6.5 is mechanical injection pump. I guess my problem is I am an industrial mechanic for a living and have always done my own work when possible. I appreciate the advice guys, still don't know what I'll end up doing. Think I'll search for a post about NA suburbans and see what people who have had them will do.

I would go with the 6.2 engine for the following reasons:

1. The 6.2 history is known (as mentioned before). This is the single most challenging aspect of installing ANY "previously owned" parts.

2. The 6.2's have a reputation of achieving outstanding highway fuel mileage!

3. I would worry about the "overheat" condition that trashed a set of 6.5 heads. Likely there is more damage somewhere...

4. 6.2 parts are just as cheap as 6.5's, sometimes even cheaper.

5. No turbo worries with the 6.2

6. If you are driving mainly unloaded highway miles, you want miss the few extra ponies that a 6.5 would have. Those 4:10 gears will be very beneficial to your power worries with the 6.2, but will also cost a few MPG's.

:grd:

Will the NA engine have the power for mountains pulling a 3-4000# trailer?
6.2 will pull that weight fairly well, but if you spend much time at all at higher altitudes, then a 6.2 will REALLY DOG out on you. Naturally aspirated diesels really start to lose power, get hot and smoke black with high altitude.

Correct TDG but the money saved by not buying the 6.5 could be used to make some improvments on that good ol 6.2. maybe a banks kit or a turbo setup from a 6.5 might also be in his futrue.

I'm doing a similar conversion...

Found a 1994 K1500 Suburban, clean body, trashed 4L60E and it's got a "cough" 350 gasser in it.

I'm wanting to gut it and install a TH700 and 6.2L with 6.5 Turbo equipment and see what it will do.

Now.. If I can talk them out of it, got a decent 6.2 to throw down the hatch.

I recomend installing the 6.2 in the project that's being discussed, mainly because you really don't know much about the health of the 6.5. You won't be able to tell from seat of pants the difference between a 6.2 and a 6.5 in a non turbo application. Especially if they will both be using a 6.2 pump. If the 6.5 has the N/A 6.5 pump on it, then it gets more fuel, which will explain more power (but less mpg).

P.S. this post would better fit in the 6.2 forum because of the vehicle, more people to relate to.

It all depends on cost. A N/A 6.2 in a burb with 4.10's and a 700r4, will yield about 20 mpg highway with decent power. The sierra's will slow it down some, but not that bad. Add a turbo and power goes up dramatically, but your 700r4 won't last as long and you will loose about 2 mpg's. I wouldn't be overly concerned with a 6.5 that has seen some high temps, it is almost always the precurser to blown head gaskets, and when the gaskets were being replaced, someone saw cracks between the valves and panicked. I would however, remove oil pan on 6.5 and inspect main webs for cracks and check out the bearings before parting with any cash.
:eek:

I actually am getting the 6.5 w/banks kit "free". My concern is time, and I am trying to make the best choice at this point. Whichever engine I put in, I will have a "spare" to get ready in case of problems. Why does putting in a turbo cost MPG (other than lead foot effect)? I would think the turbo would just increase efficiency by providing more than enough air for combustion. Can I "dial in" only some of the turbo power increase by increaing the fuel volume by less than Banks recommended 1/4 turn? No increase in volume on the IP-what will the Turbo'd engine run like?

Off topic-It is really great to have experienced diesel folk to learn from and get encouragement and or comments on my project. My friends, family and coworkers here in Silicon valley just give me a puzzled look when I mention diesel!

I would put the 6.2 in and get everything working where I was happy with it. Take the 6.5 home with you and look it over and make sure everything is ok as far as you can tell, cracked webbing, bad cylinders or pistons etc... While doing this you will have a running burban that is as bug free as possible. I might even move the banks unit over to the 6.2 and run it that way for a while. I would then decide if the 6.5 was worth a rebuild. I believe this will get you on the raod again quicker and a chance to figure everything else out while you decide if you enjoy driving the suburban or not.

Comes down to it probably will go with the 6.2, it is the LL4 heavy duty non-EGR. Mated to a TH400 3speed I got 18 MPG city/hwy/empty/loaded/light towing/mountains - nothing but oil and filter changes in 3 yrs 20k miles kinda what hooked me on these things. I was hoping to be able to average around the same with 700r4 in the Burban.