adding weight for traction

I was racing a seven year old motor and had a top five car wih that. I put in a new motor with a good cam and gained 500 rpm but no speed. im heating my tires pretty bad which i assume is from tire spin. It doesnt seem like tire spin because it seems doggy out of the hole nd it kicks in by themiddle of front stretch. could be traction loss. Should i add weight to the rear for traction? its a 1/3 mile clay track on a bomber car. It is a full size car not metric, you wouldthink its heavy enough.  

sounds to me like it has the wrong cam in it, if the cam is not coming on until the middle or end of the strightaway then it has the wrong cam for your track size.  

Rear weight will help with traction, but may or may not help your speed. If your doggy now a couple hundred extra pounds of lead isnt going to make that better. There are other things out you could look into other than just adding weight to improve rear traction. Things like like rear spring rates and rear tire pressures. I rarely ever raced above minimum weight for my class. I did race with a guy that had a 75 ish monte carlo that ran his can 400 lbs over the required weight because he said it was the only way he could get it to handle. He raced a 406 at 3800 lbs. He ran 1st or 2nd just about ever night on a paper clip 3/8 mile dirt track.

If you do add weight you will want to look for a lower rear end gear to take advantage of both the bigger cam and the added traction.