First off, why such a small cam if you are going roller? Keep in mind, the cams rpm range drops as the cubes get bigger...
Also, with propane, you will loose power vs a carb on the same engine without changing something else.
1978 Continental 460 2.50
2003 F250 CCLB 4x4 7.3 4.10 on 35s
1977 Ford Wagoner 351M/C6203/205/D60/10.25
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