Rab is probably right, getting the injector back out of the hole after using block seal
might be a challenge, but
for the price of an injector and the head (which is likely going to need replaced if you don't use the block seal)
i would look at the injector as a consumable, and part of just keeping it running as is.
depends on what you want? or need?
another option would be to remove the injector and coat it with neversieze or grease as a release agent
so the block seal shouldn't stick to the injector when it does its job, that way you got a better chance of
injector removal down the road.
just saying "if it were me" and i needed the genset to continue to keep my needs covered while i waited for replacement
parts to come (that is if i used the engine regularly for long hours) or, i would just block seal it and leave well enough alone
(that is if i only needed the engine during hurricane season for a week or so per year)
might as well get full value out of the head if possible, if you pull it down and find a pinhole you likely will never feel right about
putting it back together and using block sealer then, not unless you have to.
there is a time and place for everything, it all comes down to what your "wants" vs "needs" are i suppose.
and of course to fix it right, pull the injector, pull the head and have it pressure tested, or test it yourself.
then if you find a pinhole or crack, order a new head, gskts, and replace everything necessary, but
keep the old head! and put it up on a shelf with a can of K&W, never know when that head might come in handy
for you or someone else that is in a jamb
bob g