I have a 95 Grand Laredo that I am rebuilding and want to know what the cam size is. i pulled the shaft out it looks like its reading to fail like the metal is gettinf soft I will try to post some pics later today. I think the oil pump failed and a severe lack of maintenance.
4.0 liter

i have another question how much lift and duration can I go with out screwing with the computer?

 

OBD-I will let you get away with a little bit - but are you subject to inspections by the Air Police? That could be the problem you're more likely to run into...

As far as camshaft lobe failure, it's possible it was due to using the wrong oil for too long. The new API/SM "Energy Saving" oil has a decreased organometallic anti-scuff additive content - which is perfectly fine for roller tappet engines, but a problem for our flat tappets. Either use API/SL engine oil, or stock up on an additive like GM's Engine Oil Supplement (EOS,) commonly used as a run-in additive. Add at every single oil change, unless you know an SM oil was not used!

You'll probably find that most aftermarket camshafts are listed as "Not for use on pollution-controlled vehicles," but the milder ones should work with an OBD-I computer if you don't have the Air Police breathing down your neck.