need to know if ive been shafted.

my head went (oil seal broke and welded on to the head)
so got a stage 2 head, had that put on, but now the car just turns over whereas it started first time always.

RAC said its not turning over fast enough to start

could it be down to the cam??

this stage 2 head had done 300 miles but stood about a year.
could this be the problem?? it had no oil inside of it.

any help would be apreciated.