Swapping in the 6.5

[stepside90]

Hey, new to the GMT400 forums but I figured this was the group of die-hards where I belonged.Love my truck to death and im on the way to making it stand out and give it an edge. It first had a 4.3 in it then that came out and a 305 went in, then the 350. Which has been unstoppable in the reg cab, half-ton stepside.Mild performance upgrades just to keep the power crisp and fun.But Im on a mission haha picked up a 1995 6.5TD for a few hundred bucks and whenever I have free time will be stripping it down and rebuilding it with all the right upgrades(heavy-duty waterpump/duramax fan/ARP head studs/etc) Just wanted to see if anyone had done a 6.5 swap and any problems or advice they had.Can i beef up a nv3500 to handle it or should i really try and find the nv4500? im def going to a 14bolt semi-floater rear as im going to have a 4inch susp lift and 35 on the truck..maybe even 37s

 

[Blue95]

So will you be running it as a mechanical pump injected engine? Or computer controlled? SOunds like you have a good idea of what needs to be done and upgraded, you will definitely want to relocated the PMD to the front of the truck so it gets cool air, nice free flowing down pipe while you are at it too.
The nv3500 won't be able to handle all that torque so if you want a tranny that will last and hold up you will want a nv4500 and a good clutch.

 

[outalne94z71]

before you even think of doing anything make sure that block is not cracked, number 8 cyl is common as is the main bearing areas, you also cannot machine those cranks as the hardening is not deep enough so if the bearing surface is out of whack then you need a new crank.

also make sure you use the starter support bracket without it it can snap the ear of the block off, if you are lucky you just end up with a broken bolt.

 

[Darkrider]

So will you be running it as a mechanical pump injected engine? Or computer controlled? SOunds like you have a good idea of what needs to be done and upgraded, you will definitely want to relocated the PMD to the front of the truck so it gets cool air, nice free flowing down pipe while you are at it too.
The nv3500 won't be able to handle all that torque so if you want a tranny that will last and hold up you will want a nv4500 and a good clutch.

^^^^^ X2!

 

[frito-bandito]

Wow this is unique, most people swap the other direction! That being siad, I've always wondered if there was a such thing as a tough reliable 6.5, I hope it works out for you and can't wait to seee it all come together!!

 

[outalne94z71]

Wow this is unique, most people swap the other direction! That being siad, I've always wondered if there was a such thing as a tough reliable 6.5, I hope it works out for you and can't wait to seee it all come together!!

yes there are but they are usually not the gm built ones, bill heath's land speed record twin turbo truck is one exxception to the gm block thing but his actually started as a 599 block 6.2 and then there are the p400 amg built engines that are pretty darn tough

 

[frito-bandito]

that's cool, I've always liked the thought of a decent 6.2 or 6.5 but knew they were rare.

 

[outalne94z71]

that's cool, I've always liked the thought of a decent 6.2 or 6.5 but knew they were rare.

the good ones are not cheap, a optimizer 6500(direct replacement) is about 6k and a p400 is about 10k and you need to make a oil pan for that one to fit in a gmt400

 

[frito-bandito]

Wow!! That's pretty involved, id still probally swap a Cummins in if I wated a OBS with a good diesel

 

[Snotrocket]

Wow!! That's pretty involved, id still probally swap a Cummins in if I wated a OBS with a good diesel

The 6.5 is a good diesel it's just mis-understood. It was built to be fuel efficient more than anything else.

At one time I had a Tahoe with the 350 and one with the 6.5. The 6.5 would out tow it any day of the week and average more than 10mpg more.

Mine has 270k and counting and has never been opened up. Doesn't leak a drop of fluid, and gets 22mpg on the highway.

If someone were to swap out a 6.5 for a 350 they would need their head examined unless the 6.5 was blown and they didn't have the $$ for a new diesel block.