Re: Top feed fuel rail options
1. Racer X is cheap. ATS Racing, Hux Racing is said to be supreme cnc part of bracket / not leak / flex as per the difference in the brackets and more expensive. Lots of people use both, lots of opinions. Fuel buy the best.
2. Aftermarket Rail will flow fuel (enough). Fuel supply to the line from a single walbro 460 (largest) will run out of fuel supply at about a 1500cc injector. Rail is not an issue it’s the fuel supply as in lines, filters, pressures and pumps needed - and other fuel flow issues.
3. The rails dictate the hats - 14mm from memory.
4. Put your injectors into a postage bag and Zane at Injectors Online in Melbourne is where I have used and recommend (even been based on Brisbane). They can flow test. Injectors can’t be flow matched as in adjust what you have to match, your injectors will be dynamically different. Few people use the 2200cc injectors and for a fine tune use fuel trims, open loop idle and other tricks to make them closer to matching and working.