Blown 555 bbc upgrades
 

Iv been thinking about multi port fuel injection and the coil near plug ignition. There are obvious benefits to both modern upgrades. But are they worth it? I’ve been putting together a shopping list on the Holly website and it’s going to cost roughly 7000$ I want to be able to run the engine closer to the detonation threshold to gain that “free” power and allow the computer keep me safe while improving fuel efficacy. Has anyone done this that can definitively say whether it is worth it or not?

I'm naturally aspirated, but I did the multi port, coil near plug. Only dyno'd so far so but glad I did it.
ICDEDPPL did blown BBC, throttle body, CNP. I'm sure he will chime in soon. If I recall it was worth it just in the fuel savings to justify it.
Check my thread out. Around post 30 we start discussing CNP.

https://www.offshoreonly.com/forums/...onversion.html

is the coil near plug worth it? what rpm do you spin max? is my 7k price estimate close?

What blowers do you have? -71 style blowers need fuel blown through them to seal and lube the rotors. I’m helping a buddy do the sniper 2x4 on a triple 548 with blower shop 8-71’s this winter.

It’s a 10 71 blower currently 6% overdriven about 7.5 psi boost 7.7 static compression On pump 91 (silly CA fuel) I plan on running 12 injectors, 4 up top
to cool the Teflon and 8 for the cylinders. To keep the front cylinders from leaning out.

I don't know if CNP was worth it, but with the cost of cam and crank sensors, distributors, ignition boxes and coils the Holley Dual Sync and D-585 coils was the same cost maybe less expensive. And if you want true EFI with the safeguards of the Holley you will need to buy it. $7000 is in the ballpark for twins I believe. I haven't added the total of my systems up yet. I have it all in a spreadsheet but I haven't hit the "SUM" button. Somethings are best left unknown.