Holley Sniper EFI fuel economy

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If you have an HEI distributor you need to check your timing and vacuum. I would look at the hyperspark if you don’t have it already. I am running the sniper terminator max with the timing controller and transmission controller. I went from 6-8 mpg to 8-12 ( if I keep it under 65 mph and my foot out of it). Before I was messing with the Qjet and timing weekly. ( my transmission went out is also a factor why I switched, installed a 4l80E that was laying around). I have not had any issues after the initial advanced timing and set up. I’m running 4:10 gears, locker and 35” tires on a K20.

I would recommend against a hyperspark especially if it's a sniper 1. They are not worth the trouble over a good hei imo.

There's definitely something out of tune somewhere. A c10 with OD auto and 3.08 gears should do better than that mileage with a carb.

My truck actually got the same mileage with a 700r4/3.08 as it did with the th350/3.08. I put 3.73s in it an got better highway mileage. I think you need at least a 3.42 to keep the trans from hunting in an out of lockup an even between 3rd/4th.

 

[tadslc]

My truck with a 305 and TH350 + 3.08 got about 10 mpg.

Installed a somewhat built 350 with a 700R4 and Sniper got about 12 mpg.

Got the Sniper professionally tuned and I get about 15 mpg now.