Hey Guys,

I'm in the process of swapping blocks (N42>F54). I currently have 71 round tops, N42 head,6-1 exhaust 2 1/2 pipes with a flowmaster, and a K&N filter. I am planning to upgrade to EI and use an MSD coil. My question is about the needles in the carbs. As far as I know they are stock. I've heard that I need to change the needles with the larger engine.

Should I order the "Gross Jets" from Motorsports?

Or is there another option?

The Grosse Jets won't give you any better performance - maybe just more reliability. I've always had good luck with, and stuck with the stock jets.

As far as needles, there are different tapers that you can get. If you are pumping a lot more horse power, you need to feed the engine better. Try contacting Jeff Winter at Rallye/Sport in Colorado. He has modified needles for racing and knows a ton about these motors and carbs. He will be able to give you some great information.

Jeff Winter

303-427-0510 (MST)

7102 Raleigh St. #3

Westminster, CO 80030

I bought the SM needles and nozzels for my '73 and it made a WORLD of difference.

I picked up my stuff thru ZTherapy.

There is some great info at their website: www.ZTherapy.com

Check it out!

Brian

I secound the motion. contact them you cannot go wrong with them , they really know their stuff, this is what they do, just SU carbs. They are THE rebuilders for SUs and ship to the UK.:classic: