Had a Holley 670 Street Avenger on my '68 road runner with an old Edelbrock DB4 intake and a Comp Cam and stock exhaust manifold and Ultra Flo's.....BEST combo I ever had...changed the PV's up one size and drove it and drove it and just a no hassle turn key set-up. Liked the Holley 670 so much on the 383, when I got the '69 GTX 440 I put a Holley 770 SA on it right away...same result "plug and play"