350 to 396

[vkh]

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I'd agree you would benefit since you're doing 85mph and unloaded. I'll tell you this much though, when you get ready to tow, you're going to sure know it. Even with a Peanut Ported low end torque Fo Fitty Fo, if you're towing any kind of weight at all it's going to struggle. I found out in real life. This was a 3/4 ton 2wd roller Burb with no powertrain on an 18ft trailer. So the trailer was probably right at 1000lbs compare to the known weight of my other trailers and then the Burb with no motor I'd say 4000lb maybe 4500lb for a gross total trailer weight of 5000-5500lbs and it struggled on the slightest of small short grades. Everytime I hit a little hill it slowed way down.

I've been kind of thinking about picking up another 14 bolt with 3.73 or 4.10 for towing down the road. Then I'd just swap rears depending on what I was going to do, will all fresh fasteners and hardware under my truck I think it would be pretty easy to swap them.

 

[Shorty81]

My 86 k20, 496\sm465 3:73 years 31" tires doing any speed, empty or loaded or towing gets 10 mpg give or take.... And that's 93 octane.

 

[HotRodPC]

Actually I said a 396 with efi. I never said anything about a carb. Efi stands for electronic fuel injection

Doh, I missed the EFI. Sure glad you explained it though or I'da never got it. Don't confuse me now and tell me it's going to be TBI, TPI, SFI or DFI cuz then I'd really look stupid.

 

[HotRodPC]

I've been kind of thinking about picking up another 14 bolt with 3.73 or 4.10 for towing down the road. Then I'd just swap rears depending on what I was going to do, will all fresh fasteners and hardware under my truck I think it would be pretty easy to swap them.

It doesn't take long and not that hard. However, the awesome set up would be a 4.10 or 4.56 with a 4L80-E. I know it's pricey but depending on what your time is worth for those rear axle swaps and having a spare axle setting around....

 

[vkh]

It doesn't take long and not that hard. However, the awesome set up would be a 4.10 or 4.56 with a 4L80-E. I know it's pricey but depending on what your time is worth for those rear axle swaps and having a spare axle setting around....

My end goal is a 540 built for the street and a 4l80e. We'll see what happens but I'm hopeful. I figure even after all the money required to build it I would still have less in it than some guys spend on new trucks and have something I consider to be way cooler.