ok this is a long one so please stick with me and i apologise for my inaccurate wording etc
 i am about to fire my engine for the first time in a couple of years and break in my new cam, now we have fired it an had it running very briefly to get the timing right ready to do the break in process <it sounds amazing before you ask>  and we have noticed that where the inlet manifold meets the cylinder head there is a hole and it is exhausting out of the hole,this is due to a later manifold being on an earlier engine or the other way round. my friend who did the main work on the engine build noticed this when he was putting it back together but thought it wouldnt be a prob as on his 400 he had a different inlet so didnt blow.
 i am about to fire my engine for the first time in a couple of years and break in my new cam, now we have fired it an had it running very briefly to get the timing right ready to do the break in process <it sounds amazing before you ask>  and we have noticed that where the inlet manifold meets the cylinder head there is a hole and it is exhausting out of the hole,this is due to a later manifold being on an earlier engine or the other way round. my friend who did the main work on the engine build noticed this when he was putting it back together but thought it wouldnt be a prob as on his 400 he had a different inlet so didnt blow.He and i studied and followed rocky rotellas how to build a pontiac 400 and this is where it explained the inlet difference and where we might have a problem, in this book it explains that this hole can be filled with a hi temp expoxy thus stopping the leak.
my questions are, can i fill the hole with everything still intact carb inlet etc as the 1st pic shows or do i have to remove everything to fill the entire hole?
and also has anyone else had this problem and what product did you use to fill the gap?
i will attach some pics
thanks in advance guys


 Is that one you have at the moment Ian the white firebird ?
 Is that one you have at the moment Ian the white firebird ?