85 rebuild

If you are going to stroke it then get a kit that has the crank, rods, and pistons. Rings seem to be a builder / combination preference so let your engine builder recommend those based on the common i.e. naturally aspirated, nitrous, or boosted.

If you add displacement then the induction will need to be addressed. You have it covered with the Holley Terminator setup but the intake, cam, and heads will need to be spec’d. this could be porting the intake you have vs buying a new one and porting the heads you have (if they are worth porting) vs buying new ones.

With all that said a well sorted or 306 can make 300+ rwhp and be an absolute blast to drive.

Regardless I would suggest some 3.55 rear gears regardless the engine combo you choose. I have 3.73’s and a WC T5 and wish I had 3.55’s. A couple hundred less rpm’s at cruise would be nice and the 1-2 shift is really quick.

Car looks great and welcome!

So when you say "I can really only do one or the other upper or lower." what do you mean?

- 306 is a 302 with a 0.030" overbore.
- If the block will just clean up with a hone then you may be able to just re-ring the stock pistons. If you need new pistons and the block needs to be bored then make sure they deck the block, line bore & hone the cam bore & mains, and when the bore the block that they use a torque plate. Again, let the shop figure this out and if you need new pistons I would see if anyone on here has a set of 0.030" for sale as new pistons are not cheap now.
- As far as getting the crank balanced they will need the pistons, rods, crank, flywheel, and clutch setup to properly balance the assembly.
- Stock heads are boat anchors. Any money spent on them other than a quick freshen up for s stock motor is flushed down the drain. If the car has stock style heads (GT40's are typically worth keeping and going through) then I would get a set of AFR Renegades and be done with it. Realize you will need a set of stud mount roller rockers and most likely will need non-stock length pushrods but again the machine shop can figure this out.
- Again, depending on what intake you have you may be able to reuse it by just sending it off to TMoss and have him port it for $150 or so. He ported my Cobra lower back in the day and it greatly improved the flow. Website is below and scroll to the bottom for contact info.
- Once you know what displacement motor you are going to go with, what heads, what intake (will need flow numbers or projected flow numbers), gears, trans, exhaust setup, etc. than you can fill out the cam card for Ed Curtis and get a cam that will work with the combo. You can run the stock roller lifters on a new cam but they will need to be inspected very carefully so you may just want to order a new set. If so I would recommend these for a fairly stock setup:
I will say that Morel, Johnson, and Isky also make good lifters. The last set of Comp Cams lifters I got were a mess. Pulled them and went back to the Motorsport units.
- Headers are subjective but I like the shorties for ease of maintenance. Long tubes will build more torque and thus horse power but I do not think the gains are worth in on small displacement motors. I have shorties on my 331 but I do run custom built long tubes on the 351 in the T-Bird.

With regards to the Holley Sniper I would stay away from it as I have read a lot of threads with issues on them. The Terminator X seems to be a lot better, more tunable, and has a lot more support in the tuning forums of which one is on this site.

All of this is just my opinion so do your research and listen to the guys here as they have a lot of combined experience and can steer you in a good direction.