have a 09 sierra 4X4 with 6.2L, whipple, and ARH LT's. Wanting to rebuild motor (currently 125K miles), upgrade trans/torque converter, add muffler (delete resonator), cam, further tune and hope to get 600hp but stay drivable/reliable. A shop has given an estimate around 20K. It includes engine rebuild with forged pistons/rods, arp fasteners, methanol inj., Circle D trans rebuild with new OEM torque converter, custom cam, spintech muffler (supplied by me) installed, and dyno tuning. A previous estimate not including motor rebuild or methanol was around 11K. But the 11K estimate included a Billet Reinforced Output Carrier $1,295 (recommended for 4x4 trucks) and a triple disc converter. The 20K estimate doesn't include these two transmission parts. Roughly 7K for motor rebuild, 3K for cam/install, 7K for trans rebuild/OEM TC, 1500 for methanol kit, 300 for exhaust install, and 800 for tune. Motor and methanol charge seems high and concerned transmission/TC upgrade is missing something. Curious what others have seen as far as suggested parts and cost estimates? Should I consider stroker kit? Head work?

 

So you have a whippled 6.2 thats working fine and you want to spend 20k on the truck? It should already be making close to 600. Plenty of stock motors being pushed beyond 600 as for the 6l80 as long as its tuned correctly should last a good while.

 

With blower, headers, tune at around 80K miles...dyno sheet supplied by installer reads 435.62hp 413.02 torque, boost PSI=8.11. Two years later now at 125K miles, yes truck runs fine but looking to replace as daily driver. As such have the opportunity to make it better. Part of me says do it. Part of me thinks its a waste of money to put 600+ hp into a 6000# pound truck. At any rate, don't want to drop 20K into it and be left by the side of road with dropped tranny or ballooned TC.
Two years and 45K miles later, It still puts a smile on my face to launch from a desolate 4 way stop.

 

20K sounds kind of drastic to me. You could shop around a little and do some sweat equity - that a lot of scratch.

 

Pulley down to 12psi and let it eat. Dont waste all that money when you dont have to. 20k sounds very excessive

 

at 12PSI you may want to consider meth install. But I agree with Atomic.

 

Thanks for the input. More and more I think about it it seems excessive to spend that much on a heavy crew cab truck...that still drives well. Test drove a 15 duramax yesterday and think I might get one as a daily driver and sell the whippled GMC. Then look for a lightly modded camaro/C6/CTS-v/ or Chevy SS. Hate to sell a vehicle with a blower that I know the pedigree of to buy a used vehicle with a blower that I'd be taking my chances with. I guess that's part of the fun of it, though.

 

I agree with all comments made.I would have expected you would have made 460HP.

Your changing direction makes sense,maximize your dollars rather than dropping more $ into a 120k mile truck.

 

I would pull the motor and stoke it out - 383 or 408. Would cost a whole lot less and the end result is sweet. Just my two cents but I'm a stroker fan so...

 

and it just so happens i have a brand new 408 short block for sale!