I have another thread posted in da nailhead but haven't gotten any responseso No: I'm swappint a 56 spcl into my brothers 55 rm 2dr. I heard that the two barrel 56 is low compression, how low? Will stock 56 high compression pistons fix it? Are the heads different? I'm swapping out the two barrel intake for a weiand dual four barrel. Was thinking about using two holley 390's with adapters. Will a dual four 322 run o.k.? I would like to not dissassemble the short block, the bores looked good after pulling the heads. I also heard that the h20 crossover is different from 55 to 56. I broke mine upon dissassembly ( tried to remove it from the timing cover and left a piece in there ) I am interested in a mild 322 build-up and could use some help. Anyone have sucess with this type of build? Is a cam swap and headwork a good idea? Still need low revs with the huge roadmaster (ran like a dream with the stock 322 four though). How about a late model overdrive swap, anyone with good result? I'm tempted to try and install a 401 or 425 cause parts seem more available. Are the motor mounts the same? I know I'd have to get rid of the torq-tube. I would like the airbag the rm, customize the stance, hotrod the motor but have gennie outside chrome and interior. Well that's my story, please help me get my twin brothers first car back on the road.
I am pretty sure buick just used thicker headgaskets (or possibly 2 per head/stacked) to reduce compression on those motors as they did in the early 60s. If so just install they thinner headgaskets. If you jet the 390s down they will run all right. I agree that you can't beat the look of 2x4s but a single 500 would work better. Just go small with the carbs, you will lose some bottom end with duals. The cross over will work. Good luck.
Thanks, Dual Quad. The info is much appreciated. I looked in the buick specialties inc. catalog and saw that the pistons for all of the 56 models are the same as the 55 series 50,60, & 70. Did you have to fabricate mounts for the 401 in your 55 or did it bolt in? I see some good deals on big nailheads or donor cars. It's really tempting but my budget is limited. Did you adapt your p/s pump to the 401 or adapt the 401 pump to the 55? What tranny did you use? Do you know if you can keep the torq tube if you run a 63 w/ dynaflow? Thanks again, Kevin
