Definitely need a 3.08 with any of them 4 speeds, my 84 caprice that i had came with a 2.73 with a 700r4, which was ok, but you can definitely get away with (and be much happier in the fun department) with a lower gear. A perfect street combo would be 3.55 gears with a 2000rpm stall with the 700r4, youll be able to smoke the tires or tire for a mile lol but anyway, for the motor, if you do decide to change the cam a good cam for the street on a near stock low compression small block would be a dual pattern, with around a .400 lift on the intake and a .420 on the exhaust, a 112-114 LSA and somewhere around a 200 degree duration @.050 with a bit more on the exhaust side, but that will be a given with a dual pattern cam. If your sending the block to the machine shop have them deck the block to 0, so that way with a .040" standard fel pro 7733pt gasket, your quench will be perfect. I know its more expensive and may not be an option to you, but if you can, just change the pistons to flat tops, and bore it a standard .30 over. That way you will bump the compression up, and it will be a really happy street motor.
I know 700r4s are more plentiful and a tad bit cheaper, but why choose this one over the 2004r? The 700's dont have a very great gear ratio and 1st to 2nd shifts are always hard due to the 1st to 2nd gear ratio. Ive driven many cars with the 700 and every one of them had the same characteristics. And thats totally up to you im not bashing these transmissions or your decision. Just thought id throw that out.