Getting ready to build the 4.3 in my 2002 ZR2. I have a similar post in another subsection but doesn't seem to be getting much attention. Need input on aftermarket cams and machining required for use in the 4.3. I have already procured a marine intake and plan on using stock exhaust manifolds and 2-1/2 single exhaust. Looking to gain around 50HP. Please post your cam specs (manufacturer and part numbers if available) and what mods/machining were required to run your cam. Did you have to change the valve train to adjustable? Choppy Idle? What RPM range does it pull best at? If you had it to do it over, what would you do that was different? I know this is a lot to ask for but I have been researching this for about 9 months and have been getting conflicting information and the cam manufacturers aren't much help at all.

Here is what I have learned this far, please correct me if wrong.
Current engine has hydraulic roller lifters.
Most aftermarket cams use a different base circle (requires adjustable valve train).
500 lift and above requires machining (but what machining are they talking about)
May require deeper valve relief in pistons (don't want to go there)
May require taller valve covers depending on rocker studs (don't really want to go there either)
Will require a professional tune. (got that covered)

Not looking to build a straight line car, will be my daily driver. Just need a little more punch for getting around in rush hour traffic and the occasional bass boat pull.
Thanks in advance for your informative input. Oh and last but not least.......because I don't want a V-8.

 

As you said, you have another thread concerning this subject, so a duplicate is unnecessary. Anyone looking for the original thread, here it is:

https://blazerforum.com/forum/engine...upgrade-98434/

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