[injun9]

Originally Posted by baron_

what size motor?

Might I recommend a 650 for a 400

and probably a 750 for a 455

I used a 750 on a 389 for a while....it was too large
It lacked good signal


In an ideal world, you'd use one with annular boosters. There's a reason CSU installs those on all its carbs

It's 194.5 CI's.

[injun9]

Originally Posted by Johnny406

This is a real good starting point and reference.

http://www.hangar18fabrication.com/blowthru.html

This site has a really good starting point. In the article it talks about how to boost reference the throttle shafts. But never mentions it again. Do you know if there is more on this some where else so I can read up on it.

Thanks again.

[baron_]

It's not mentioned much because it isn't a necessary modification if you're keeping the boost relatively low

I have very, very! minor leakage at 15lbs
Nothing to worry about unless you're going to insane levels



194.5? One of the early 4-bangers?
And what size holley are you working with?
I have a buddy running a 550 with great results on a chebby 350

You don't need as large a carb when working with blowthrough. In fact, smaller carbs are nicer...as you'll see better atomization, response

[injun9]

Originally Posted by baron_

It's not mentioned much because it isn't a necessary modification if you're keeping the boost relatively low

I have very, very! minor leakage at 15lbs
Nothing to worry about unless you're going to insane levels



194.5? One of the early 4-bangers?
And what size holley are you working with?
I have a buddy running a 550 with great results on a chebby 350

You don't need as large a carb when working with blowthrough. In fact, smaller carbs are nicer...as you'll see better atomization, response

Yeah , Its a 1961 4 cyl. I'm running a Holley 650 double pumper.

After I get a decent tune and feel for it established I will be pushing it. So I might be reaching boost's in the 18 to 20 lbs range.