i just bought a 63 mercury comet convertible for me and the family. car runs well, but slips out of park, and only reaches about 50 mph. how do i fix the parking, and get more speed out of her. dont want to make it a race car, but just accelerate well from 0, and comfortably cruise the highway at 70 mph or so. what combo of engine/tranny/carb should i look for, or is there a certain way to calibrate parts to achieve this? thank you all in advance.

Lets start with which engine is the Comet,144 cu in I6 170 cu in I6 260 cu in V8 ...If you have the 260 all performance parts of the 289 will fit on it, or just the stock 289 parts can make major gains over a 260. Comet with the Fordomatic two-speed? right, column gear selector. Ann Arbor, MI

it does have a 2-speed automatic transmission, but i am not sure the exact model of engine, it went from the guy i bought it from into the shop to get some exhaust work, will be back in a few days.

If its a 144, that is probably about all you are going to get out of her, depending of course on the rear end gearing, Most of the 144s have really steep gearing because the motor was so underpowered, If it were me, and If it is a 6 cyl, I would swap out the 140 or 170 for a 200 I6 from a mustang, maverick, etc.... (Not the 250, the 200) Get the auto that comes with the 200 it will likely be a C4, this will give you a 3 speed transmission, You can do this swap without changing much, If you can find a 200 from a mid to late 70s car, it will have electronic ignition too , its a breeze to set up on your old car Then with the added torque and hp of the 200 you can go for a tall gear, I converted my 61 falcon from a 170-3speed manual 4:10 gear top speed maybe 60 or 65, to a 200 C4 and rear gear of 2:79 , now it cruises all day at 70 or 75 , Drove it from east coast to the Midwest with no problems, Its no race car off the line but more than adequate. I don't like converting the 6 cyl falcons to V8s even though a lot of people do it, there is a lot more involved than just dropping the motor / trans in, especially if you want to do it right . The V8 cars had completely different suspension, axles, strut rods etc.. plus they had torque boxes in the unibody to handle the added torque of the V8. On a Convertible, this could be downright dangerous if you didn't do it right

Oh, the reason it slips out of park is likely the detent in the steering column, does the shifter feel loose?

thanks alot for the help guys. the motor is a 2.8liter 170 with 1 barrel carb, not sure of the tranny. i need a new exhaust system, trying to design one now. the shifter is automatic and it doesnt feel lose. in fact, its a little tough to get out of park sometimes.

By tough do you mean it feels stiff or you have to "jimmy" it? The detent in the steering column could still be the issue, if you have to monkey with it to get it out of park The detent is basically just apiece of metal with steps cut into it. This thing controls why you have to pull the shifter towards you to shift into gear from park, if its loose in the column or damaged you could have odd issues See this image The smaller oval shaped hole is for park, there is a pin that goes into it, You normally have to pull the shifter towards you to release it from this hole, If the shift linkage pops out of park as you say, likely the pin did not engage, if its hard to get out or in, then I would guess that the issue is something to do here, either the pin is damaged, bent, or otherwise messed up, or the detent is loose or broke, wore out this is a c4 detent that falconparts sells, but yours will look very similar If your car still has the door tag, check the axle code, if the rear axle is stock, this should tell you what your gear set is the axle code should be 2,3,5 or 9. the taller the number the steeper the gear