I found two spare leanburn 1.6 cvh heads in my garage. One has 88sm6090 on and the other has 91sm6090. The first one is from my standard 88 xr2 and the other is from my 92 mk3 fiesta 1.6s I scrapped years ago. Is there any difference? I need to send a head off for porting and the 91sm head has no scoring on lifter bores and the cam bearings in the head are score free whereas the 88sm head has some scoring on a couple of the lifter bores and very mild scoring and a strange bronze stain all the way round the cam bearing. On both heads on the cam bearing on the pulley side there is a notch on about 2mm long. Is this meant to be there?
Cheers

 

Ask your head man?

I would say they should be the same but i would send the laster head off

Not sure a 88 head has hardened valve seats? i may be wrong?

 

Google

Cvh tuning guide pumabuild

There was the best guide about for them with all the codes and info on each

 

P.s a efi xr2i head is the best for big ports and big valves