So the cooler months are ahead of us, and Im looking to be working on the car this winter in the garage. So for my 66 Pontiac, it comes with a 389 with AC. It does run, but does need a tune up badly. still seems to run smoothly though.
1)It only has a 2bbl carb on it currently... I do want to upgrade to a 4 barrel carb though in the upcoming months...
What intake manifold would you recommend, finding a stock cast one? Or edelbrock performer or any other opinions? And what carb should I look for?
2)Should I do just a tune up and intake, carb? Or should I do a basic engine rebuild as well at this time? If I can, I would prefer to wait to do a stroker kit though...
You will get various opinions. I would suggest not ripping into it big time at first, i.e. an major changes. If the 2 barrel is working good enough to drive, I would focus first on getting it safetied and drive it a bit. Find out what little things it needs and slowly pick away at those. So many guys dive in head first on a "new" car and end up getting discouraged.
If you are bent on doing a 4 barrel right away, see if you can find an intake and carb, complete setup, still on a running engine or very freshly removed (last couple of months). If not, you have to count on the carb needing a kit. Changing to a 4 barrel isn't always as easy as it seems. It can mean different brackets, fittings etc and you can end up opening a can of worms by taking that on.
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
If you decide on a 4 barrel intake and carb do not rule out an original gm Pontiac cast iron manifold. I read a few dyno comparisons on Pontiac intake manifolds and there was little to no performance improvements with going to an aftermarket aluminium intake besides the weight difference. If it was my 389 engine I would look for a complete intake and carb assembly as Carl has suggested from another 66 389 engine. I am a firm believer in original manufacture parts. GM Ford and Chrysler spent millions of dollars on engineering especially on high performance in the 60.s. Professional marketing firms are paid a lot of money to promote products whether the product is an actual improvement or not.
If you do change the intake, make sure when installing the intake that you snug up the bolt that pulls the manifold forward first before tightening the other bolts. I remember seeing lots of firebirds with lots of silicone trying to seal the coolant leak at the joint where the intake sits against the back of the timing cover.