The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - My swap. 5.3 into a 1990 3/4 ton 4x4 Suburban.

justcuz · 03-26-2012, 07:27 PM

Looks real nice!
My only concern with installing these engines in older trucks is the cam torque curve. I have a 2000 with a 5.3/4l60E/3.73 gears running 285/75x16 tires. It gets better mileage at 80 than at 65-70 mph. I heard that GM lowered the operating rpm range in the 6.0 engines cams in 2011. Does anybody know about this? BTW by better mileage I mean 17.75 to 18.13 mpg on Interstate 15 through Utah on my way to Wyoming. It normally gets about 2 to 3 less mpg when going 65-70. Actually am considering a 4.10 gear swap to get better mileage...or maybe the 6.0 cam if it runs at a lower rpm range.
I have to admit that before considering a big block or diesel engine swap I would definitely consider this swap before anything else in an older vehicle.

03-26-2012, 07:27 PM	#89
justcuz Registered User Join Date: May 2008 Location: Alta Loma, Ca. Posts: 930	Re: My swap. 5.3 into a 1990 3/4 ton 4x4 Suburban. Looks real nice! My only concern with installing these engines in older trucks is the cam torque curve. I have a 2000 with a 5.3/4l60E/3.73 gears running 285/75x16 tires. It gets better mileage at 80 than at 65-70 mph. I heard that GM lowered the operating rpm range in the 6.0 engines cams in 2011. Does anybody know about this? BTW by better mileage I mean 17.75 to 18.13 mpg on Interstate 15 through Utah on my way to Wyoming. It normally gets about 2 to 3 less mpg when going 65-70. Actually am considering a 4.10 gear swap to get better mileage...or maybe the 6.0 cam if it runs at a lower rpm range. I have to admit that before considering a big block or diesel engine swap I would definitely consider this swap before anything else in an older vehicle.