I have a stupid question. I is probably in here somewhere but I can't find it. I want to know what rear end I have. I have a set of 308s sitting around from my 81 TA. That rear end is a 10 bolt 8&1/2". I am hoping my rear end is the same size. It's in a 91 RS. I have 274 in it now. Also would it be worth while to put those in or should I get bigger ones? I am putting a 330 horse vortec 350 in as we speak. I am also rebuilding and putting a shift kit in the trans. Should I put a stall converter. I was thinking around 2500. I love this form. I have learned so much about these cars. The engine swap is allot more difficult than I thought. The trans and rear end I can handle. I want this car just to drive on the street, but... when one of those shot nose kids pull up next to me at a lite in a little rice burning piece of ****. All sounding bad, with a 20 dollar exhaust, and a cheaper stereo. I want to blow them away, not just laugh like I do now. The 305 gets the car around but that's it. It's pretty embarrassing. I am so proud to be an American that I always buy American but... I would like to prove their superior and squash the non-American's that are driving those f***ing rice burners.

 

You have several questions. First of all you have a 10 bolt rear end. I could only make a guess as to the gear ratio being 2.73. The 3rd gen 10 bolt rear is 7.5 inch ring gear and the 91 is 28 spline axles. The 2nd gen 10 bolt is as you said 8.5 ring gear. As such they will not interchange. The early 3rd gen 10 bolt rears (up to and including 89 I believe) were 26 spline axles.
For the engine swap are you going carb or staying EFI? It should be fairly straight forward. Unhook all wires and fuel lines and hoses. Disconnect throttle and TV cables.
Unbolt the motor mounts and trans mount. disconnect the shift cable and torque arm. Lift motor and trans out. Set new in and bolt up the motor mounts and trans mount. Hook up hoses and wiring for gauges, throttle and TV cables, shifter and torque arm.
If carb adapt fuel lines and pressure regulator. Put in an HEI dist and use wires to and from coil for power and tach.
As for a stall we need to know what cam you are using. You will probably need or want a better exhaust.

 

Thank Dude. I looked better and found the info but thank you very much you told me alot. Now I need to buy gears. What ratio would you go to? I still want good mileage but want a little more snap off the line. Also what brand? I know it's best to get factory gears but sometimes they are hard to find. How about the stall converter? Yes I am staying TBI and it is far from easy to make the change to a 350 from a 305.

 

Your 7.5 with 2.73 gears will have a 2 series differential. If it's a posi and you want to use the same one then you are going to need a set of after market "thick" gears to fit this differential. If you don't have a posi then I recommend getting a new Yukon Dura Grip or Eaton Posi in a 3 series and get the standard thickness gears. I would recommend a 3.42 for a street car with an overdrive transmission.

 

For the TBI with the vortec engine you need to find a vortec style TBI intake. Then put either a whole 350 throttle body assembly on from a pickup and try it or use the 350 injectors in your 305 throttle body assembly. If you are upgrading the 350 much you can always try the 454 injectors and possibly the whole assembly with some modifications. It should run good as long as the cam stays reasonable.

 

Vortec engines came out well after the 3rd gens stopped, so I'm wondering where you came up with talking about Vortecs to start with.

Th3 TBI 3rd gens were not Vortec engines. The Vortecs were truck engines in the late 90s.

 

He mentioned putting in a vortec 350 in the first post. I am assuming he is talking about the 96-2000 truck engines.

 

Ooops. Sorry. I looked before speaking but still overlooked it. I blame the lack of the capital V!

 

You made me double check so no problem. I will never complain about being corrected when I am wrong as we are all trying to help.