I have to put new intake manifold gaskets on my LO3 305, so I figured i might as well buy a better intake manifold for it while its all taken apart anyway to replace the **** part that GM used. BUT, since the LO3 is a TBI system, I either have to use a special intake manifold built for the TBI system, or use an adapter plate on a carbureted intake. Now, this is what I'm not sure about; can the Holley TBI adapter plate be used on the edelbrock intake manifold? I would much rather use this technique for replacing the intake manifold then buying the TBI intake from edelbrock for $100 more then the carb intake manifold. I'll put the links to the parts below. Also, I will be using the factory TBI from the LO3


http://www.holley.com/17-41.asp - adapter

http://www.jegs.com/i/Edelbrock/350/2104/10002/-1 - intake manifold

 

Holley makes a tbi intake also.
The adaptor you need is depending on the intake style, spead bore (q-jet) or square bore.

 

When I was spending my own money, I opted for the Genuine GM TBI-to-Spread-bore adapter from a late-80's 454. It's taller, and has provision for heating it via engine coolant.

I'm not a fan of the Holley adapter, I think they've placed the TBI too far forward for best fuel distribution. That's a hunch, not a verified fact. Take your chances.

Looks to me that the Holley adapter he's linked to will fit either spread- or straight-bore manifolds.

The manifold he's linked to is drilled for spread- or straight-bore carbs.