Hi I have a 61 Invicta with a 401 Nailhead. I would like to change over from the single 4 barrel to a dual quad set up which I do not believe was an option in 61. I have the opportunity to buy a dual quad with carbs and linkage from a 64/65 Riv - 425. Is this a bolt on? I am not sure if it is interchageable. I wonder if the manifold and carb will clear the power steering bracket in the front as mine is mounted up top, just in front of the manifold? I would have to buy air cleaners , etc but I assume I could get something. I am going more for a custom look under the hood Also, does anyone know the cam specs for that year and was there a difference between the 401 and 425? Also, fuel pump? Was it a single or double diaphram? Any help would be appreciated, I am just learning Thanks Tim
Tim, I hope that someone has replied to you already about the intake swap. I know that the manifold will physically bolt on to your engine, but the P/S brackets may need some attention to get them to fit. I would hope that someone has done this swap before and does get back to you on the particulars of the swap! HTH, Tim McCluskey
Tim, The dual quad was an option on the 425 from 64 thru 66, the intake will fit all 401's. I have an offenhouser dual quad I'll sell if your interested, but it might create a hood clearance problem due to the fact they sit higher then the stock cast iron unit...JJT
dual quads... i just finished installing dual fact carbs on my 64 401 wildcat convertible....i took it for its first drive tonight.....all i can say is awsome!!!!!!!!!!!!!!!!!i used a obrian trucker finned air filter top with some custom base plates that saved me 1 1/2 in height...i also had to have a kickdown bracket made and the dist recurved...both carbs were" restored" when i bought them on ebay but they were seized up from the bead blasting getting into everything....so after many long nights i fully disasembled them, cleaned, rebuilt and installed them....it runs great....lots more power...looks cool...todd h i will try to post a pic this week
I found an old engine book and it said the 401/425 cames were different. The 401 has longer duration and the 425 has higher lift. If you need the specs please email me at buickgnw@yahoo.com. P.S. the 425's had the same cam Thanks! Hank
