I need help!

I am currently working on a marine 454...on the exhaust manifold is a heat riser and over the last few months or years it has leaked sea water all over the block and starter...I was doing a tune up for the owner and upon my pre inspection I discovered the #5 cylinder plug wire was off and the spark plug had rotted out of the threaded lower quarter....now I must remove the Exhaust manifold etc..to fix the problem...now I have rust build up all around the bolts and when I looked in the manual it calls for loctite on the threads and it made it impossible to remove the bolts....I tried everything I could think of...I used a socket for stripped bolts, I tried to manually spin the bolts with a hammer and chisel....I am now thinking of a grinder to remove the bolt heads but wanted some advice before I do this.....Does anyone have any suggestions?

 

I have had exhaust bolt in the same shape. I found if they are too rusty, and most of the bolt head gone. I would cut the head off, and put wd40, or (loctite makes some thread penetrate that is pretty good) on the bolt and let it set over night. In most cases, it came out so-so easy.

At least with the head cut off, there is still some bolt to get a hold of. If you brake it off. Then that makes for allot more work.


Travis