I'm thinking hard about upgrading the stock Rochester throttle bodies on my 575SCI's. Thinking of going with the FAST 4150 style 4bbl throttle bodies with built in injectors.

Has anyone here done this conversion? AZ Speed & Marine recently sent me this pic of a kit they offer that includes new harness and fuel pump system.

Can these style TB's plug into the existing harness? Adapters? Also would the stock fuel pump/plumbing be up to the task @ 750-800hp?

I think Steve Zuckerman is over 750hp with stock fuel system. I know you can send your stock tbodies out to CFM Tech and they will modify them to flow better...zuckerman also had this done. If you did go the CFM tech route, make sure you send the adapter plate to the blower as they will machine it and match it to the tbodies.

You could go this route also...never seen an offshore boat with this setup but I always thought it would be cool and also save hatch clearance.

Nice looking package. Got a link to check out?

http://blowerdriveservice.com/cart/ymm.php?cat=22_50

Thanks for the link. Would look very cool!

You can call Alex@ Haxby Speed and Marine. Holley has a TBI set up that will replace the stock.

The FAST throttle bodies that you are talking about will work great. The problem with the stock setup is that not only will you start to run out of injector around 750 hp, but you also have the injectors sitting right in the venturi to disrupt the airflow. I have seen a few guys swap over to the FAST setup and they seem to work great.

Another route is to put together your own setup. You can buy an injector plate like shown in the kit above. I wouldn't use the injector hat setup. Tip in (just off idle) is really tough to control. THat's 3 really big holes that open at once. It's almost an all or nothing deal. It makes docking fun All you need is an injector plate like shown, a side saddle carb adapter, 2 1000 cfm throttle bodies, injectors, fuel pump, regulator and some plumbing.

Or, if you are handy, you can make the injector plate and fuel rails yourself. When I need one to hold 10 or 12 injectors, we just make them. No one offers one with anything other than 8 injectors, so we made our own. It's not really that hard. It just takes some time.
Let me know if I can help in any way.
Eddie

Eddie love the fact they are sitting on PSI'S!

We never got to use them. The customer changed his mind and ended up going with 4.0L Quadrotor WHipples. He sold the PSI's and intercoolers. I still have the injection setup if anyone is interested.
Eddie

OK, here is a thought. What if I used an injector plate (like the one I pictured from BDS) and installed the stock Tbodies on it? This would allow the original injectors to be machined out and also may allow the stock linkages/air cleaner to be utilized. That should increase flow and get rid of the sub par stock injectors. Just a thought for an easy conversion.