Would i have any issues with valve to piston issues if i put a cam with .550 lift in a Stock NA 6cyl?

Read this of FTW site

Head
- 4L has larger ports in the head standard and repond better to turboing if used totally unmodified
- 4L has larger inlet and exhaust valves standard, 4.1L has room for bigger valve but this get expensive doing new valve seats etc
- 4L will flow around 430 hp, the 4.1L around 410hp when ported to the max virging on hitting wter jackets, with big valves etc.
- 4L has a bigger chamber so you only need 11CC dish to get 8.5:1 compression where the 4.1L needs the 27.9cc dish piston
- 4L valves are more canted so they need valve reliefs cut into the pistons, 4.1L engines have plenty of piston to valve clearance

peak lift has nothing to do with piston to valve clearance, At peak lift the piston is about half way down the bore.

Its lift around TDC that is your issue

Hmmmm how do I work that out?

Is there some sort of calculation I need to use.

Thanks for your input from what I have seen on this forum you know alot about cams

you could hazard a guess buy plotting a lift graph of your stock cam and then comparing the peak lift of the new cam with your lift curve but that's dodgy as and barely accurate.
Only way to know for sure would be to plot a lift graph of the new cam.

Get hold of the cam specs from the grinder/manufacturer, then find someone with a motor and head, and spend 10 mins with a dial indicator and some plasticine on the piston.

you need to measure the lift that contact occurs from about 15degrees before and after TDC.
then find out from the cam grinder what sort of lift the cam has in the same range.

I have the cam specs from manufacturer

Thanks for the advice and I will ask the manufacturer the required information as requested

cheers