The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Gas mileage increase- six to BB OD

ZEKE68 · 11-29-2018, 08:38 PM

Just wanted to post this for who ever is interested, but I replaced my 250 six Powerglide trans with a .030" over 454 and a overdrive automatic and got over two miles per gallon better mileage. Always got around 9.8 to 10 with the old power train. Just got 12.3 mpg the last tank with the big block overdrive.

11-29-2018, 08:38 PM	#1
ZEKE68 Registered User Join Date: Jul 2012 Location: Space Coast, Florida Posts: 408	Gas mileage increase- six to BB OD Just wanted to post this for who ever is interested, but I replaced my 250 six Powerglide trans with a .030" over 454 and a overdrive automatic and got over two miles per gallon better mileage. Always got around 9.8 to 10 with the old power train. Just got 12.3 mpg the last tank with the big block overdrive. __________________ 1968 SWB Step Side, Big Block, 4L80E , Running!