Hi all,

I'm restoring a '74 Delta 88 convertible that came with a 455 originally, but at some point had a 403 fitted from a '77 Cutlass. The intention is to someday put a 455 back in but for now I'd like to keep the 403 cause all the funds go to restauring the chassis/body atm.

Now, this 403 had headers and a 9755S 750 cfm carb fitted with an adaptor plate, and I'd like to keep it and just rebuild this (as you can see it needs it badly).
But my question is: is this an adequate carburettor for this engine? It's got the original 4A heads and no headwork done (I assume, also: is there an easy way to check if it's got a cam fitted?). I has a full MSD ignition system tho, so someone at some point threw some money at it.

I don't think the jets are right too because the plugs were all a bit dark.. I'll include some pictures.

Thanks from Belgium

 

It should work, 750 cfm is the right size for a stock 403 but an air fuel gauge is by far the best way to tune it. It could be way off from where it is supposed to be.

 

Okay thank you very much!! She's a keeper then. A buddy of mine has a dyno so we can probably get it right on there after installing the engine. Maybe just some minor adjustments on mixture will suffice?
Thanks again, appreciate it!!

Greetings from hellhole Belgium

 

Get a good assortment of jets and rods for the dyno run. Rebuild it, see what it is in it and get a couple of sizes down and maybe a couple of sizes up for jets and a size up and down on the rods. Good luck.

 

Okay thanks, I'll do just that when the time is ready.. great info!