offset of the rims can play a part in that too

 

Do not under estimate a 305. I only have an open element, 3 IN. cat-back, and the engine base timing is advanced 4 degrees. It throws you back in the seat. Barely hit the gas and the wheels spin. Driving 30 and floor it the wheels churp. All this with 178,000 miles on original motor and auto tranny.

 

Hey. Sorry to beat a dead horse, but I switched from 2.73 gears to a posi 3.73 gears. How do I adjust the timing?? And is that good to do?

 

Here's a sticky that explains how to set the timing. = https://www.thirdgen.org/settingtiming
Not all of us have the skill set or the equipment to use step # 12
There is a more primitive way to do it.
As far as it being good to do,I'm going to say yes.It made a large difference with throttle response.Very nice off the line.It really gives my car that extra pep I was looking for ,of course there are other upgrades that are working hand and hand with the bump.(new posi.,new 3.42 ratio,Corvette servo. for the shifts,etc.)
I will give you a little tip. Add more information to you signature about what you are driving. Go to "User CP,then "edit details" and fill in the last 4 questions. This way at a glance we can see what you are working with and that helps us answer some of the questions being asked.