MicroSquirt.com read only forum (Jan.15,2018)

I'm replacing a Holley Projection Di 504-2 900cfm system with a MS-II and am looking for a TBI that can flow around 750cfm. The engine is 355cid Chev small block, AirFlowResearch 210cc heads, Edelbrock Victor Jr. intake.

So it looks like the 454 TBI 2" bore with some airflow mods, 85lb. injectors with higher pressure would able to keep up. Some posts at http://www.454ss.com forum mention ways to increase air and fuel flow. I'd rather use OEM parts and not custom throttle bodies or TBI to keep the costs down and make it easier to find replacement parts and sensors in the future.

Anybody have experience with 454 or other high flowing TBI's?

Thanks,
keil

The holley part # 502-20S, is a 670cfm TBI with 85 lb injectors. Similar to the GM 454 2" TBI unit but without and IAC stepper. It has an adjustable pressure regulator, a fast idle solenoid, and barb fitting for the fuel inlet and return. I suppose the body could be drilled out to accept a standard GM IAC. It is the throttle body that is included with there pro-jection system.

The Holley injectors seem to have a bad reputation. I was looking for a big block TBI unit for one of my projects, but they seem to go quickly from the wrecking yards and ebay prices get a little outrageous. I managed to find a Holley unit that had a bad injector pod. I replaced that pod with a GM pod and bigger injectors, and the total cost was less than what I would have paid on ebay for a big block GM unit. My Holley base was one of their 5.7l replacements, and it has a TPS and IAC.

Those big-block TBI's are expensive! I looked into using one myself before I decided to go with a holley 4bbl TBI.