Over 150lbs, U need to run a higher octane mixture usually 50/50 of 100 or more octane..
From DLNOSS website
Approximate Cranking Compression
These pressures are estimates based on fresh stock bore, piston, porting, and deck height.
It is recommended to check your compression after installation.
Sea Level 1000' 2000' 3000' 4000' 5000'
18cc 238 229 221 213 205 198
19cc 211 203 196 189 182 175
20cc 184 177 171 165 158 153
21cc 157 151 146 140 136 130
stock 130 125 120 116 112 107
Hope this helps out