I picked up a complete 4.0 fuel injection intake manifold to use on my turbocharged Buick 300 build. I'm fabricating aluminum spacers to account for the width difference as well as a custom valley cover. It's my understanding the the trumpets can be shorted once the other intake is apart but after removing the bolts I'm having substantial difficulty getting the 2 sections apart. I'm using a pair of TA Performance Rover heads on this engine and while the Rover intake ports are a bit undersized for them I feel that will help throttle response and low rpm Torque. The Turbo should take care of the upper rpm airflow issues. Any tips for getting this apart?
AFAIK there is no gasket between the upper and lower manifold. There might be glue or sealant but nothing mechanical once the bolts are removed. Gentle whack with a hammer should get them apart.
I have used non hardening sealant during assembly.
Rob,
I also have a similar application, although my 300 will not be turbocharged. I also have a complete 4.0 manifold and injection and plan on either replacing the trumpets with wider/shorter ones or at least shortening the ones I already have. It's my understanding that if you put the manifold in the oven (after taking everything else off), you should be able to free up the trumpets. I'd be interested i seeing your adapters for the manifold, as I intend to do the same thing. I might make mine out of high density fiberglass composite, to insulate the manifold from the heat of the engine--not sure if you've thought about that.
Mine is sealed with a rubbery sealant. I can't even get a razor blade between the 2 halves. I'm going to bed lt the intake to the engine and use more persuasive options.
When removing my trumpets I put the plate in the gas bbq at 400F for 10 min or so. Worked well and no fumes in the house. Maybe you could do the same for your upper intake?