I have a 41 Ford coupe that I want to put parallel springs on both ends of the car but I have no idea what is the typical length for the springs? I have a straight tube front axle and a 9" out back.
The longer the spring the better the ride. By 1935 Ford had figured that out hence the wider/longer springs starting that year. By '41 they were even longer. I sure wouldn't swap out the buggy front spring on your '41... the frame is pretty narrow for that... keep the buggy spring as they can ride and handle pretty well. Out back you want the longest spring you can get. it should be shorter from the front spring eye to the center bolt than from the rear eye to the center bolt... that will stiffen it for less spring wrap on acceleration. You'll also have to design in some "anti-dive" if you want the rear to get forward bite... something the original Ford has right from the factory. All in all Henry had a good suspension in his pre-'48 rides... most aftermarket rear parralel kits don't have a good spring in them... too short and no anti-dive.
alot of the aftermarket kits use springs that are the same as dodge 4x4 front springs. Several i hafve seen use Toyota 2wd truck rear springs in addition
I used to build a fat fendred spring kit using the Dodge 6 cylinder front springs from the I think mid 70s. It's the same style spring CE uses now.
I'm in the planning stages (still trying to score affordable "free" parts) for installing parallel springs + 9'' axle in the back of my '41 Business Coupe. So this is an awesome thread for me too! My question is...Why would you want a parallel set-up on the front?
Well I had intended to run a straight tube axle and I still might. I have had some opinions that that isn't easy driving or safe, But thats what the gassers ran back when.
You can try this, Grab the spring hangers off a chrysler 5th ave or dodge diplomat. 1983-86 or close. Check out the springs under a bronco ll. this should get you close. take a walk around a junk yard,and take measurment.(spl) Hope this helps russ