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mbeach
05-17-2005, 05:10 PM
yo troops. was going to change out my spark plugs and found different ones installed than what manual recommends. manual says use an ac mr43t. ones i yanked out are ac mr43lts. looks like the 43lts is a longer plug. my engine is an indmar (gen motors) 5.0L mx plus 275 hp. any suggestions?? 2 dealers i spoke with say use the 43t but why would anyone install the 43lts other than the 43t's were not available and they were in a hurry. any thoughts??

Engine Nut
05-17-2005, 08:30 PM
yo troops. was going to change out my spark plugs and found different ones installed than what manual recommends. manual says use an ac mr43t. ones i yanked out are ac mr43lts. looks like the 43lts is a longer plug. my engine is an indmar (gen motors) 5.0L mx plus 275 hp. any suggestions?? 2 dealers i spoke with say use the 43t but why would anyone install the 43lts other than the 43t's were not available and they were in a hurry. any thoughts??

The guidelines for the 5.0 and 5.7 are the same. If it is a vortec engine (8 intake manifold bolts that go straight into the heads) it uses the MR43LTS long reach plugs. If it is a non-vortec, (12 intake manifold bolts that go into the head at an angle) it uses the MR43T short reach plugs. I suspect you have a vortec engine because if you used long reach plugs in a non-vortec engine you would probably have have seen the piston hitting the spark plug.

Engine Nut

mbeach
05-17-2005, 08:41 PM
The guidelines for the 5.0 and 5.7 are the same. If it is a vortec engine (8 intake manifold bolts that go straight into the heads) it uses the MR43LTS long reach plugs. If it is a non-vortec, (12 intake manifold bolts that go into the head at an angle) it uses the MR43T short reach plugs. I suspect you have a vortec engine because if you used long reach plugs in a non-vortec engine you would probably have have seen the piston hitting the spark plug.

Engine Nut
many thanks nut :worthy: . this will help. just very interesting that the manual calls for the mr43t, however. hence, you see why my confusioasdfinasdfnasdfasdf9i.