Intake not seating down between heads

[BOWTECH.JUSTICE]

Following up to my previous thread of my 1992, 4.3 mercruiser, serial # D829937. I got a rebuilt through Summit Racing and my intake won't seat down between the heads as it is hitting the top unmachined part of the top rail of the heads. The heads on the old and the new heads have different dimensions on the machined face for the intake. Old face is about 2.75" wide of the machined face and the new is 2.50". The top rail above the machined face measures 1/2" on old and 3/4" on new. Cast #s for the old heads are 10144103, new-14094768. Cast #' for old block are 10172756, new-10105867. I'm being told from Summit, and ATK the engine mfr., that for some unknown reason my old motor has these odd ball heads and intake. I guess my questions are- is this true? Does anybody know why? and is my best option just to bite the bullet and add more to the cost by buying an intake?

 

[Walt T]

You bought a Vortec motor to replace a non Vortec engine. Nothing wrong with that, it makes more power. Not a lot, but more. You have to buy a new intake. Get one specifically set up for your current fuel system.

 

[Bondo]

Following up to my previous thread of my 1992, 4.3 mercruiser, serial # D829937. I got a rebuilt through Summit Racing and my intake won't seat down between the heads as it is hitting the top unmachined part of the top rail of the heads. The heads on the old and the new heads have different dimensions on the machined face for the intake. Old face is about 2.75" wide of the machined face and the new is 2.50". The top rail above the machined face measures 1/2" on old and 3/4" on new. Cast #s for the old heads are 10144103, new-14094768. Cast #' for old block are 10172756, new-10105867. I'm being told from Summit, and ATK the engine mfr., that for some unknown reason my old motor has these odd ball heads and intake. I guess my questions are- is this true? Does anybody know why? and is my best option just to bite the bullet and add more to the cost by buying an intake?

Ayuh,..... How many bolts hold the intake to the heads on yer intake,..?? How many bolt holes in the new heads,..??

 

[BOWTECH.JUSTICE]

12 bolts on old and new. After a week of researching and calls to the mfr., I'm being told that some reason GM had these odd ball heads and intakes for a couple years that they used in bigger trucks and I just happened to be lucky enough to get one. They have all been helpful and they admit that they have never ran into this before. So what I have done is scribed a line on the top of the intake gasket and there was 3/16" excess above the gasket and the cut off both sides with a metabo blade. Sounds a little rough I know, but had room to work with. So as of now, the intakes is on and the motor is ready to be put in tomorrow and on the lake Tuesday. (Hopefully).