Grit dog
Full Access Member
- Joined
- May 18, 2020
- Posts
- 7,090
- Reaction score
- 12,473
- Location
- Auburn, Washington
- First Name
- Todd
- Truck Year
- 1986, 1977
- Truck Model
- K20, C10
- Engine Size
- 454, 350
I’d second the 4L80 swap if you need OD.
Other things to consider, first figure out what gears you have and add a tach to see if it really is screaming.
These are “higher” max rpm engines than you might expect.
Redline is 3600 with a load and I believe 4000 max.
Of course you don’t want to put up with 3500 rpms all day, but if its 4.10 gears, you may be close to that with those tires at 70mph. For comparison, my 4.10 turbo400 truck is at 3000rpms at 70mph (gps, still need new speedo gear to correct speedo) with “35s” that are sitting at an actual 33.5” diameter.
If you’re towing 5klbs even at sea level and flat, I would NOT gear the axle up at all. 6.2 is pretty anemic and would struggle with tall gears towing IMO.
First see what rpms you’re actually running at your desired cruising speeds. If it’s not that bad, maybe a muffler is all it needs for your driving pleasure!
That burb is really nice btw!
Other things to consider, first figure out what gears you have and add a tach to see if it really is screaming.
These are “higher” max rpm engines than you might expect.
Redline is 3600 with a load and I believe 4000 max.
Of course you don’t want to put up with 3500 rpms all day, but if its 4.10 gears, you may be close to that with those tires at 70mph. For comparison, my 4.10 turbo400 truck is at 3000rpms at 70mph (gps, still need new speedo gear to correct speedo) with “35s” that are sitting at an actual 33.5” diameter.
If you’re towing 5klbs even at sea level and flat, I would NOT gear the axle up at all. 6.2 is pretty anemic and would struggle with tall gears towing IMO.
First see what rpms you’re actually running at your desired cruising speeds. If it’s not that bad, maybe a muffler is all it needs for your driving pleasure!
That burb is really nice btw!