got a 55 chevy car want to put a 396 in it. it has power steering stock manifold that hits the steering box. do they make headers to go around it or do I have to do something to the steering box?
got a 55 chevy car want to put a 396 in it. it has power steering stock manifold that hits the steering box. do they make headers to go around it or do I have to do something to the steering box?
There are a dozen way to put a BBC in a 55, some work better than others. I personally believe that at least 1.5 forward is necessary. It is not available in a kit that I could find so I used Ecklers/CCIs 2.25 forward and my headers clear my 500 ps box, I can easily get my v/c off my 396. Plus I did not need a BFH on my firewall.
i have motor stools that move the motor 3/4 inch f0rward. is that going to be enough?
Sam, whatever you choose is a compromise. Further forward lessens valve cover clearance problems but also means the oil pan will hit the steering, and less room up front for fan to radiator clearance. Stock location means some serious firewall mods for valve cover clearance. 3/4" forward is a compromise that many use but you still have to clearance the firewall slightly and will have to have a modified oil pan. Another thing that's affected by fore/aft location is clutch linkage if you have a manual transmission.
Thing is, fore/aft location of the engine has little to do with steering box clearance to the exhaust. There are full length headers on the market that will clear a power steering box. Header clearance to other things besides the steering box may be affected by fore/aft location.
Another thing you can consider is moving the engine to the passenger side by 1/2" or so. The newest design of Earle Williams side mounts allows some side to side adjustment. They can mount the engine in the stock fore/aft location or 3/4" forward just by swapping the parts that bolt to the block from one side to the other. The other advantage of this mount is that it doesn't use the old stock style rubber/metal mounts, which are very poor quality these days.
I have noted that there can be variance between individual cars depending on how car is positioned on frame.
The body mount bushing sleeve is 7/8" ID and the bolt is 3/8" OD so the most the body can move fore and aft is +/- 0.25" from center. Since there is a tolerance on each body mount position, it's actually less than that.
I have found that at 1.5" forward you can clear the stock firewall with the heads and valve covers. But as mentioned, you start running into problems with interference with the steering mechanism.
My belief is that if you are going with a custom firewall, leave the engine in the "stock" position to avoid oilpan issues and potential radiator clearance issues with the accessories. The "stock" position is where the back of the block on the BBC is at the same location as the stock SBC. The engine mounts on a SBC and BBC are located at the same distance from the back of the block, but a BBC is around 2" longer forward of the mounts.
If you want to leave the stock firewall intact, go 1.5" or more forward and deal with the oilpan issues. It's not that hard to get an oilpan that works, and headers clear better with the engine moved forward anyhow.
56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension
Other vehicles:
56 Chevy 2-door BelAir sedan
56 Chevy 210 4-door sedan
57 Chevy 210 4-door sedan
1962 327/340HP Corvette
1961 Willys CJ3B Jeep
2001 Porsche Boxster S
2003 Chevy Silverado 2500 HD Duramax
2019 GMC Sierra Denali Duramax
When I wanted to in stall a Big Block in a Trifive I bought a kit like this from Ecklers. https://www.classicchevy.com/chevy-b...1955-1957.html
" Moves Engine Forward 2-1/4" For Maximum Firewall Clearance, Requires Use Of A 6-Cylinder Position Radiator, Includes: Engine Brackets, Headers, Transmission Crossmember Kit, Deep-Sump Oil Pan & Pickup & Column Shift Linkage, For Use With 1965-90 Big Block Chevy."
Everything bolted up to original frame mounts, no cutting or bending. They have several kits with different options such as, auto trans, or manual trans or other header coatings, etc. Not the cheapest way to go, but the easiest.
That looks like a decent kit. When I was doing mine I had it in my head that the motor must go in the "stock position". I don't know if it was due to listening to some at another group or what made me do it. Tall valve covers would require some major firewall mods. Right now the firewall isn't "massaged", it's been beaten with a 10lb sledge hammer. It was done long ago before I knew any better. Since I've been having fun going to the drags, I'm happy I left the motor back that far. If I were to pull the motor for some reason, i might consider a BBC cut and weld in firewall piece, just the part for the engine if they make it like that. I hate the looks of those flat firewalls, to me it's just a few steps away from making the fenders and everything else flat.
I'm running some Speedway headers that they swear fit, you would never know it with all the hammering I had to do to get them in. Left side hit's the steering box real bad and the pittman arm and the right side hits the idler arm pretty bad. The may be due to the factory power steering, those arms are different.
Tony
1955 Bel Air Sport Coupe