I am in the process of heads and cam. My car is a 1994 firehawk and I have the non-vented opti. In order to go with the heavy duty timing set, I am going to swap the opti for the 1995+. My question is on the cam and the timing sprocket. Correct me if I am wrong but the cam shaft on the non-vented setup is a bit different then the vented. Will this present a problem? I noticed that the camshaft has a longer pin and the center whole is bigger. Will this be a problem after or during the swap? Thanks for the info. This is the page that I referenced. I am also going by these gm part #'s.

http://para.noid.org/~muttvette/opti.html

 

You want the longer dowel pin and larger hole for your conversion. That is what the vented opti needs. Just make sure the pin is not too long (sometimes an issue with a Comp Cam). It should protrude no farther than .685" from the front of the cam. My stock pin was .650".

 

So, my new cam will need these specs....ok...what about the guys that are just upgrading their timing chaines, stock cam will not work then am I correct? Because it has the smaller hole and the pin is shorter correct? When I speak with the cam company, do I tell them that the cam must be for a 1995+ f-body or how will they know?