hey guys I need your help I wanted to know if I need to rebuild my transmission (4l60-e) on my 2000 Camaro A4 before I do heads(243) and cam (MS4).

 

The first question is - do you really want an MS4 cam? Many members here would say not for a street/strip car:
https://ls1tech.com/forums/generatio...p-ms4-cam.html

http://www.corvetteforum.com/forums/...e-with-it.html

As mentioned, you won't see much benefit unless you shift at 7000+ RPM and for that you really should have a performance built 4L60E, 4000+ stall, 3" exhaust, modified heads to handle .675 lift and much more. It will be a bitch to tune, tend to stall when cold and have all kinds of negatives.

If you still have the stock cam, an upgrade to a MS2 (or equivalent) cam with a 3600 stall will blow your mind and you can then more gradually upgrade the rest of the car in as you ever decide to get a much hotter cam.
Hey, just my opinion.

 

How much horsepower are you expecting to make with the head/cam swap? Are there any other upgrades already installed? And is this going to be a street car or do you expect to do a lot of hard starts from a standstill?

 

Well right now I have pacesttter long tubes, off road y pipe, borla Exhuast, and lid and ls6 intake and I am hoping to have at least 420 hp with the cam and heads

 

Then it will mostly just depend on how you plan on driving it. A lot of hard starts with decent tires on the track or even on the street will probably warrant a level 1 or 2 rebuild from a sponser just for piece of mind. If your just giving it some gas from a roll for some highway fun then you can probably get by stock.