Any "must do" upgrades for 403?

[rebelgtp]

Well the last couple days I have been working on scraping all the crap off my 403 to get it ready to go in the Cutlass. While I have this thing out and it is easy to get to everything is there anything I should look at doing? Not looking to go extreme with this engine, it will basically just be a fun street car until I come up with the funds for building some sort of forced induction engine (maybe a stroker DX block build since I have one in the shop). So yeah for now just something reliable and fun is all I am out for right now. It will have TH350 behind it and the rear is a 7.5 with 3.23 gears and posi.

 

[STL84Calais]

Get a 5 main Halo Girdle from J&S for some insurance for your bottom end.

http://www.jsmachineoldsmobile.com/home.html

 

[L92 OLDS]

Replace the rear main while it's out. A timing chain and high volume oil pump wouldn't be a bad idea either. A girdle is a good idea for an all out build but for a stocker I would skip it - just don't over rev it. I don't have one on my 12 sec 403 and it has held together for 25+ years. A good line bore and balanced reciprocating assy has helped...

 

[Randy_W]

For a fun street car it'll hold up fine, to make it more fun a good ignition curve, with plenty of advance, a good intake and properly working Q-jet and a set of headers with 2.25-2.5" duals.

 

[DoubleV]

Assuming you're just taking apart a stock 403, cleaning it up, and reassembling it and are just looking to add a bit more oomph for cheap and little hassle, then I would put a bigger cam in it. The stock ones are so small. Even with the stock crap compression, a bigger cam would make a difference.

When it's all together, a nice exhaust system combined with your new cam should really wake it up.

P.S. If you have a set of older 68-72 350 heads in good running shape, you could slap those on too ( do a search for specifics about bolt hole size ) which would make a big difference too. With the 350 heads, you'll get more CR so you can use an even better cam.

 

[rebelgtp]

Yeah though about both the cam and heads. Sadly I only have 350 smog heads available to me at the moment.

 

[L92 OLDS]

Assuming you're just taking apart a stock 403, cleaning it up, and reassembling it and are just looking to add a bit more oomph for cheap and little hassle, then I would put a bigger cam in it. The stock ones are so small. Even with the stock crap compression, a bigger cam would make a difference.

When it's all together, a nice exhaust system combined with your new cam should really wake it up.

P.S. If you have a set of older 68-72 350 heads in good running shape, you could slap those on too ( do a search for specifics about bolt hole size ) which would make a big difference too. With the 350 heads, you'll get more CR so you can use an even better cam.

Good advice ^^^^^^^^