Hello, and welcome to the forum.

It's neat to see non-Chevy engines getting EFI. I have a friend with an early Poncho fullsize convertible and 455 that's done an EFI swap using a 4bbl manifold with PFI. It's a very cool project.

I'd like to meet the person or people who convinced you the Crossfire system was no good. Usually a poorly working system wasn't the system's fault. But it's not built for what you want to do. It's two single throttle bodies that flow as much as the stock smallblock Chevy TBI.



You can see some pictures of what folks do to the stock manifolds here. It's hard pressed to support over 300hp.

Dual TBI as a first TBI swap project is a big step. There are some challenges in making sure the fuel system will supply both TB's properly and in building a proper throttle linkage which can be synchronized for matching throttle angle. And there's distribution issues in the manifold but those may be secondary if you have a proven manifold. There's wiring but it's not that much worse than a single TBI retrofit. PCM choice could be critical to making this work. Electrically the ecm / pcm must be modified to work with four TBI injectors and of course there's the actual work of tuning this combination so I'd choose the 16197427 or contact Dynamic EFI for an EBL ecm. It's not impossible but it is going to be more work than a single TBI swap.

2bbl TB air flow is measured at higher vacuum than a 4bbl carburetor so the flow numbers you find are not directly comparable. As mentioned, the large bore 454 TB's are the ones to get. Tuning for good street operation will take some time so if you get frustrated quickly with an engine that doesn't run right you might want to practice on some stock or mildly modified vehicles before tackling this one.