360 with 273 manifolds

[swing69]

I posted this question in early A forum too: basically, how can the 273 cast iron manifolds be optimized with a 360 LA engine????? picts? port matching? instructions?

What % am I losing in output vs. spitfires???????????

thanks

 

[krazykuda]

You can port match them to the exhaust gasket.

Then try to clean up the ports inside a bit. I did this on a 74 charger and broke through where there was a "scallop" for a bolt clearance, but welded it back closed and finished porting it.

 

[273]

There's a dyno of 318/360/340 and magnum manifolds on a 300hp plus 360 and theres little difference between them, I would port match though

Manifolds vs shorty headers, depends on your power out put a 500 hp engine gonna lose more power than a 250hp engine saying that maybe 10 hp

 

[moper]

The problem isn't the head to manifold junction... It's the lower section of the driver's manifold that is about 1/2" deep and 2" wide before it makes the 90° bend into the Y pipe... It sucks and there's not much you can do if you need to run them. You'll lose some, just accept that it will still be a lot more powerful than a 273 powered car.

 

[pishta]

I posted this question in early A forum too: basically, how can the 273 cast iron manifolds be optimized with a 360 LA engine????? picts? port matching? instructions?

What % am I losing in output vs. spitfires???????????

thanks

Can you run magnum logs? Very good flow compared to 273 or even 360 castings. Narrow and cheap.