The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - thinking about maybe dropping a big block in my truck

tucsonjwt · 08-13-2011, 11:23 PM

In my experience, a full size old truck - 350 or 454 - will both get about 10-12 mpg. city, maybe 13-15 highway, depending on loaded weight and rear axle ratio. Some will say they get much better mpg, but I never have.
So, although BBs are more expensive to buy and rebuild, they are not as popular as SBs because they have the reputation of being gas hogs. I see trucks advertised in CL with recently rebuilt 454s or good running 454s for very few $$. My 73 C20 with stock 454/TH400 was one of the fastest vehicles I have owned.
If you want a real scary fast hot rod it will cost you big $$ to do it right - SB or BB. Or, just buy a truck with a good 454 already in it - they are all over the place. But a word of caution - it's not the engine and transmission that are the big cost - it's all of the other stuff on the truck that you will have to replace over time that eat a hole in your wallet.

08-13-2011, 11:23 PM	#13
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,198	Re: thinking about maybe dropping a big block in my truck In my experience, a full size old truck - 350 or 454 - will both get about 10-12 mpg. city, maybe 13-15 highway, depending on loaded weight and rear axle ratio. Some will say they get much better mpg, but I never have. So, although BBs are more expensive to buy and rebuild, they are not as popular as SBs because they have the reputation of being gas hogs. I see trucks advertised in CL with recently rebuilt 454s or good running 454s for very few $$. My 73 C20 with stock 454/TH400 was one of the fastest vehicles I have owned. If you want a real scary fast hot rod it will cost you big $$ to do it right - SB or BB. Or, just buy a truck with a good 454 already in it - they are all over the place. But a word of caution - it's not the engine and transmission that are the big cost - it's all of the other stuff on the truck that you will have to replace over time that eat a hole in your wallet.