318 power?

Kinda depends on what you want to do.
Since we really don't know anything about the cam, why not wait and see.
It is my opinion that if the cam is just one or two sizes over stock then you may be able to control wheelspin with larger tires.But it won't be particularly quick out of the gate with the 2.76s, and a stock TC. But if you are just gonna cruise it, then wait until you you have had a chance to drive it.But, if the cam is any bigger than that, then a rear gear change and/or a higher stall TC will very likely be desired.
- On the otherhand, if you wanna have some fun, then a 3.55SG and a 2400TC are a fun place to be with a warmed up teener. And if you really wanna wake it up a3.91SG will be a blast. - But if you need to spend significant time on the hiway, then 3.23s or less will be nice.

- Performance gears do several things, the top three being; 1) they trade away cruise comfort, for off-the-line giddy-up, and 2) they allow the engine to rev up a little quicker, which accelerates the car a little quicker, and 3) they make your engine feel bigger.
Additionally; the higher cruise rpm sometimes leads to heat,wear,noise, and vibration issues.
- As to #1) the switch point is about 3.55s. Cruising with these and 27 inch tires puts the Rs at 2867@65 locked up.I cannot say where the automatic might slip to.Some guys are ok with this, others like me, not so much. Plus it won't get any awards for fuel savings.
- As to #2) Quicker is funner.
- As to #3) 3.55s will make your engine seem 3.55/2.76 =about 28% bigger! This is a huge improvement.
- As to the SureGrip; You might be able to get away with a non-SG with 2.76s to 3.23s,the stock TC,and decent big tires. But it really depends on your driving style, and the engine output at stall. Which is very dependent on cam size, and,of course, the stall rpm. I would be adopting a wait-and-see approach. Well that's not quite right, but it's what I recommend for you.