simplex or duplex on a xflow with piper 285???

[grunty-motor]

i am rebuilding my xflow with spec as above and big valve head, double valve springs / 1300 pistons in a 1600. Now when i first built this motor some 20yr back i did it with a simplex vernier timing gear. i did about 20kmiles like that

my question is whether a duplex is needed or not? the engine has done maybe 20k set up with the simplex but maybe i was lucky???

for the life of me i cant remember why i bought a simplex back then - someone must have told me it would be fine...???

[Graham]

duplex isnt vital, but the timing chain lasts longer before stretching so it stays in tune longer

[grunty-motor]

i was planning on fitting a new chain and pad anyways so think i will stick with the single chain as its all verniered in

cheers

[racing escort]

I would stay with single but new chain !

[dbrw1]

I'm running the same spec on a new single with no issues.