97snakebite

Alright, I understand there's a difference between the 96-98 cobras heads as opposed to the later years. The 96-98 have what's called B-Heads as opposed to the later models C-Heads, is that right? What's the difference between the two?[/align][/align]Also, can someone explain to me exactly what Intake Manfold Runner Controls are? And why have I seen that some people have deleted them? Sorry if it's a n00b question, I'm just not really sure.. lol[/align]

ponysnake99

96-98s have whats known as a dual runner set-up. There are two sets ofports on the heads to match the runners, one round, one square. The airflow in the runners varies with the port shape, in this case the square is always open, providing flow characteristics to improve bottom end performance. However, at a certain rpm, the IMRCskick in and open a set of rounded butterflys, boosting top end hp and providing more flow. Now the imrcs get deleted because without them, there is two constantly opened ports to flow even better (two heads are better than one idea).

darcnytemare

hmmmm....see I learn something everyday. Good question to ask because I had no idea what IMRC even stood for

IMRC=International Mustang Racing Club

mustangman36578

+1

the main difference between the B and C style heads are that the ports are a lot different. it has one port going from the intake runner to two valves opposed to the square and round ports that are secluded which gives them a lot better flow.

exhaust port is a different shape too.

Dilireus

You can't swap one for the other without changing exhaust and intake as well.

97snakebite

Awesome. Thanks for the information, very useful.