The 848 head thing is based on the 58 and engine specifications as 8.5 CR compared to the 56-57 8.0, and I guess the 54-55 7.5. A good number of years ago, Tom Langdon and I were discussing the CR of the various heads. Tom was still at GM before he retired and he actually looked the numbers up with the 848 heads (which entered service for the 1956 model year) at 79.1 cc and I think 86.0 for the 5913 head. I have to check my notes on the exact cc so If I am off a little I will correct it. One of these days I will have to cc one of my 56-57 heads and a later 61 head and see if there is any difference because I have never been able to sort out where the 8.5 CR for the 58 and up motors vs. the 56-57 motors came from. That being said, by the time you deck a block during a rebuild, and surface a head, I think the difference in CR between the 848 and 5913 heads becomes negligible.
Btw, I ran a 5913 head on a 57 block for quite a few years with dual carbs, hot cam, headers and it ran really good (I still have the motor) so I would not be overly concerned about sourcing an 848 head. As for headers, you have Fenton and Williams as the cast iron possibilities, Clifford for the true tube header possibility (although they only sell a shorty header these days no long tube versions like they used to have years ago, and not cheap at any rate), the crappy tube manifolds you see on ebay (both plain steel and stainless, I would take a pass on these), and finally, converting a stock manifold to dual outlet or true split.
As for the intake, you can use exhaust gas to heat the bottom of the manifold, but frankly the two little copper tubes for the fentons and Williams are not all that efficient. Hot water is better.
Last edited by Dragsix; 10/11/2019 4:13 PM.
