Power (with good torque) is not all just in the head, it is more in the cam + carby these days.
Stock, the 1275LS was about 59HP; nowadays you can get over 100HP at the crank with a single HS6 or HIF44 SU, and stock 1275LS head porting, just with Mk2S intake valves fitted. Using an RE13, RE83 or RE266S cam. Use 1.3 or 1.5 rockers (1.3 on the 83).
The stock 1275LS cam is pretty useless if you are chasing good power.
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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.
