Can any of you guys give me a hand with this one.

I purchased a Holley 300-64 intake manifold to mount on my L03 TBI engine. So I need that adapter to mount the TBI onto the Carb intake....Now I know this is something which any machine shop can make fairly easily...but for simplicity sake and the fact that I want this thing ASAP I have decided to just purchase one already done.

My problem is that Holley has two different ones....a HLY 17-41 and HLY-17-45. Which one do I need for the above intake and the stock TBI unit. I have tried emailing Holley but they have not been all that responsive....ideas???

Thanks,
Dave

 

Try www.cfm-tech.com thats where I bought mine from. Showed up in 3 days.

 

17-45 is for square bore carb mount.
17-41 is for spread bore (quadrajet) mount.

 

What is the difference between Spread bore and Square bore???

I know they are different but how would i tell which one I infact need. IF it helps I know that a Edlebrock 750 Carb I have lying around fits on the intake I have.....thanks guys.

 

I was wondering the same - I got the Weiand Action Plus #8000 intake. Advance Auto can order them both for next day delivery - one is half the price of the other, so I thought I'd just get both and see (when the time comes).

 

Square bore:


Spread bore: