Sanderson Headers for my 63 Riviera

I have a nice set of headers for the 364-401-425 Nailhead. They have been sitting in their boxes for years. Someday I may attempt to install them, but just as I want to install a factory set of dual quads, it will be strictly for looks. I suspect that I gained about as much performance by cutting the lightening holes in my trailer hitch brackets (2 hours - eight ounces) then I will get from the headers. But damn, they look cool!

 

Gary,,,, my theory on the nailhead intake is pretty much reflected by the Doc dual plane mod outlined in the sticky.... :Smarty: I really had to look a the different possibilities before I did the first one,,, I thought , if I do this , there is still the restrictions in the carb throats and that is impossible to change:idea2:... except by changing carbs,,, did not want to do that , already had it set up for a holley,,, and then there was the air cleaner situation,,, again already set up for a holley carb... holleys are very free flowing carbs... so ,, I put my confidence in them and went with opening the stock manifold up... and i was amazed at the difference... not so much on the low end,, but a bunch on mid range and high end... I think Buick did a good job making the intake for stock purposes , but what if they had done what I did ,,,, I think that in a side by side comparison a nailhead with a factory 2x4 set up would come up second best with a DDP manifold and a big holley or other carb.... all other things being equal.... but to get street performance , you must have heat in the manifold... first off , it is a ''divorced'' manifold and as such runs much cooler than the sbb or bbb.... that is why you need the heat , to make the fuel you get now flash into a vapor,,, back in 1966 the public could buy real gasoline,, not the epa cat pee you get now.... it would flash much quicker... so today more than ever before you need the heat... cold air going into the intake/carb,, to the warm manifold, fuel flashes and we are on our way.... :Smarty: The DDP mod increases the amount allowed in,,, the only restriction is the carb... put a 800/950/1050 cfm holley on , and you are really free flowing.... :Brow:

 

Thanks, Doc!

 

Excuse me for a basic observation on the original exhaust topic. I just learned from recent research to NOT install exhaust manifold gaskets on the 401. Next time under the hood I'll have to remove them. Why would Fel-Pro include them?
However, I'm all for those who help us with parts and equipment!

 

In theory, if both the head and exhaust manifold flanges and "square and true", the gaskets are redundant and not necessary. If you've got them installed, they aren't hurting anything. I've installed mine without and both manifolds leaked like a sieve.

 

heads dont warp much,,, but can be trued up.... manifolds warp the most ... and can be trued up.... put a straight edge on each and see which is out.... and then true them up again and they will work just fine without gaskets on them...

 

The metal-metal fit is for heat dissipation. Gaskets tend to insulate/isolate & NOT transfer heat the same. You need to take the manifolds to the machine shop & have them "trued" up & NOT with a belt sander as doing that rounds the edges. Make sure they get cut squarely.


Tom T.