Hot Rods Let's talk Cadillac 331's, 365 and 390's

I am dying to see the outcome.

 

Oh, Man!

 

Me too! The only thing is I don’t know how accurate the numbers will be on it because we are using the dyno Holley 4 bbl on the stock intake, instead of the 6x2 drag star because I don’t have the Strombergs ready yet. Also the stock exhaust manifolds instead of my chrome headers because they want to install O2 sensors

 

You Cadillac guys might get a kick out of this 55 Chevy Wagon. Phil Stevenson drove it from Southern California in 1972 up to Bonneville. It had a 390 Cad with a Jetaway trans. and made runs in the 140s. Back then the SCTA had an award for the fastest car driven there and he won the recognition.

 

Some simple, yet slick work in there, she'll be a cracker

 

I hope there are a few break in runs and at least a couple power pulls for a graph. How big is the dyno carb? I mean it's not the drag star setup .. but if it's the late 390 intake it should work well no? I hope you get it to 400hp.. but maybe I'm crazy hoping for that. Are you going to rev it to at least 5500 as well?

 

Not sure on the carb size, he did say it was easy to change the jetting without removing the bowls. I have a 650 double pumper I was going to use but he suggested using the dyno carb. Hoping to get one horse per cube so around that 400 hp would be great. We plan on a couple power pulls to see what it likes for timing and fuel

 

I know for the math 650 likely works fine but in reality I wouldn't be surprised if they put a 750 or larger on that thing. Either way I'm excited to see your results as I'm about to start a 390 build myself.

 

some great and innovative info on this thread since I last visited!

 

Thinking about making a small run of this alternator bracket arm I fabbed up yesterday. Local fab shop has a CNC plasma. If I get enough interest I will get prices. Works on 390’s with the accessory hole and a small Denso alternator.

 

Did you ever get the Caddy on the dyno?

 

We did. The stock 4 barrel intake only flows 400 cfm and with the stock exhaust manifolds it put up numbers a little better than factory. Once I get the Strombergs done we are going to run it on the dyno again with headers.

we did play with oil pump pressure relief springs a bit and found we were able to get the cold idle pressure to 60 psi, 30 psi hot idle and 50 psi at 5000 rpm with the engine up to temperature. I’m pretty happy with that. We ended up putting in a double spring and one of them I believe is from a duramax. I’ll find out more information to be sure

 

Nice good to hear an update. I can only live vicariously through others building a Caddy right now. I don’t quite have the funds to start into my 390 sleeping in the garage although I did recently stumble onto a Weiand dual quad manifold that I’m hoarding away. I also don’t have a Model A for it to reside in yet either.

 

I'd be interested to know what the O2 sensors told you about the mixture distribution for all the cylinders...

 

Interesting stuff, Thanks!

 

I would say you could lean it up a bit on the big end and gain some power but that is a safe tune for sure