| J&S MACHINE Work In Progress Typical 403 build using KB pistons ported 4A heads etc... |
| J&S Machine supplied the 403 block-machine work - Halo Girdle for Dick Miller Racing EMC Build. Which is featured in this article of PHR Mag.!!!!! |
| Jim @ J&S 410 cu in 403 |
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| 4A heads in progress |
| KB pistons |
| FROM THIS !!! - |
| TO THIS !!!= |
| As cast 4A 403 heads : 83 CC , 1.5 ex valve 2,0 intake |
| J&S Stage II work on factory as cast 4 A heads.The exhaust side is key to making a 403 breath.Old seat are machined for new seats and oversize valves |
| As seen here new seats are now larger on id than old valves were on od |
| Ex. dividers welded with full port and all new guides-Will outperform stock as cast e-brocks on a 403 |
| Finished Stage II 4A heads , 2.07 intakes x 1.71 ex. Flow 257 cfm intake x 190 ex. |
