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BossHogg69 · 09-05-2017, 08:47 AM

The cam/specs you have now IS the best blend of performance and mileage. If you get a big enough cam to actually notice a difference over what you have now (like 218* @ .050" or bigger), you'll need a higher than stock stall in the torque converter to get the most out of the new cam and then your mileage will start to suffer.

In my '65 Bel Air station wagon (daily driver) I have a small cam in it similar to what you're running and I get 17mpg in it with 3.08's & TH350 w/stock converter and 28" tall rear tires. It's a 350 with an Edelbrock performer intake & Holley 650 vac sec 4bbl carb.

In my '05 GMC w/5.3, I put a 215* @ .050" cam in it, mileage stayed about the same (18), but then I installed a 2600rpm stall torque converter to take full advantage of the bigger cam and promptly lost 2 mpg.

18mpg in your truck with a strong 350 is great. If you're happy with it now, I'd weld the hood shut and drive it.

09-05-2017, 08:47 AM	#7
BossHogg69 motor exploder Join Date: Mar 2009 Location: Pittsburgh, PA Posts: 2,346	Re: Cam vs mpg The cam/specs you have now IS the best blend of performance and mileage. If you get a big enough cam to actually notice a difference over what you have now (like 218* @ .050" or bigger), you'll need a higher than stock stall in the torque converter to get the most out of the new cam and then your mileage will start to suffer. In my '65 Bel Air station wagon (daily driver) I have a small cam in it similar to what you're running and I get 17mpg in it with 3.08's & TH350 w/stock converter and 28" tall rear tires. It's a 350 with an Edelbrock performer intake & Holley 650 vac sec 4bbl carb. In my '05 GMC w/5.3, I put a 215* @ .050" cam in it, mileage stayed about the same (18), but then I installed a 2600rpm stall torque converter to take full advantage of the bigger cam and promptly lost 2 mpg. 18mpg in your truck with a strong 350 is great. If you're happy with it now, I'd weld the hood shut and drive it. __________________ Adam 1969 Chevy CST/10 stepside, DART Big M/TREMEC Magnum Extreme/3.73's w/Detroit Truetrac 1965 Chevy Bel Air Wagon (daily driver), 327/TH350,10 bolt w/3.08's 1961 Chevy Bel Air Sport Coupe, ZZ454/M21/9" rear w/3.50's & Detroit Truetrac 2005 GMC 1500 ccsb 2wd, 6.0L/4L65e/3.73 G80 2006 GMC 2500HD ccsb 4x4, DMax LBZ/Allison 6spd/4.56's w/Detroit TrueTrac Use the SEARCH function on this forum - it is your friend!! Last edited by BossHogg69; 09-05-2017 at 09:55 AM.