For anyone that has answered questions on my threads I apoligize if I am throwing too many on here. I just have a lot of questions as a new classic car owner. The backround is I bought a 70 cutlass that did not have the original motor in it, but was given that numbers matching 350 motor with the car which I plan on rebuilding and putting back in. Being a 70 motor I have researched a little and found that those are a desirable year for the motor. If I have the motor beefed up do I need to change out the tranny and rear end? I know it probably matters what is done to the motor and if that is the case what could I do without having to change the rest of the drive train. The car has the original 3 speed auto tranny and rear end. I haven't checked yet to see what gears I have. Does it make the car worth less if I do change the motor than if I just rebuild it to factor specs? Any thoughts or ideas would be great. Thank you

 

looks like a nice car, I'd keep it close to original but don't worry about mods, just make sure you keep original parts. I think it will be worth more with the original block in it but modifying the internals to get a little more pep out of it wouldn't hurt value. Posi would be a nice thing to add, would probably add value to most people - its your car enjoy it - if it was a rallye 350 or a W31 I'd say leave it completely stock.

 

Ok, do you have any ideas of what I could do to beef it up. Or is that a question better saved for the machine shop I bring it to

 

Make it what you want! There are many threads on here for motor upgrades to almost any level to fit your needs.

 

Close to original to resto-mod will keep it worth the most money and the most people interested if you sell it. Custom paint and body mods and most custom interior can make it loose value fast. Tires, wheels, suspension, brakes motor mods, (or upgrade to a big block) all seem to not effect the value and sometimes help it.

 

Since you actually have a numbers matching engine for your car, you may want to check into a couple things before doing anything. First, would be finding out more details about the engine installed in your car, as could be a rather beefy build. 2nd would be checking into possible other mods, like added dual exhaust system, different tranny, or axle ratio change. Finally, find out the actual true value of you're particular car, leaving it all numbers matching. If nothing really special about it, let the mod's begin.

 

Make the car how you want it. If you want performance go with a pump gas friendly 455 , it will cost about the same to overhaul as your 350.

 

You can leave the numbers matching engine out and rebuild the engine that is in there now. That way you leave the original, original and do whatever you want to the engine that is in there now.

Your transmission should be fine. But, you may want to convert the peg leg to an anti-slip differential.

 

is it a two barrel or a four? If its a two I think you could increase the value a bit by getting a stock cast iron four barrel intake with a nice quadrajet. Do a nice dual exhaust system off the manifolds, a slightly bigger cam with a modern grind that will still idle and a little lower gears out back. I have never heard anyone complain that their car doesn't have the 2.56 it was born with. The need for originality & pedigree go hand in hand. The more special a car is the more the value is effected by not being original.

 

Keep the car you have now as original as possible, and, since car guys have unlimited funds, buy another that you can play with

 

in my opinon i would build the matching motor to have a bit more power and put it back in there but change the rear gear to some thing better as an all around gear the 3:23s in my rallye seems to be pretty good, its a whole lot better to cruise in than the W31 with the 3:91s