I don't have a muscle car (wish I did) but I do have a '72 Dodge motorhome. Of course the RV forums don't have much info regarding the motor I have, so no better place to go than somewhere people work with them.
The motor I have is the 413-1 and have been able to find some info, but not alot. I am sure I have the 413-1 and not the 413-3 because I have the original equipment sticker from the motorhome. The thing only has 78k miles on it and has been sitting since 1998. I did put some fuel to it and have heard it run, so that has us excited. Now I just need to go thru and check/fix everything and change fluids.
One question I have is with the exhaust. Are these engines prone to exhaust leaks? Would a set of headers increase my towing torque, or just top end hp? And lastly, would a set from a 440 fit my 413? I have been told they are basically the same motor, is that true?
I have some basic info on the motor that was included in the original owners manual (which I also have) but do not know much else about it. They quit using these motors the year after I was born, and I've never had a "RB" motor, so if anyone can offer any literature, info, coments, advice, etc. it would be greatly appreciated.
Thanks, Dave

 

you do not want headers, they are noisy and getting the starter off is VERY hard, most of the power gain is at the high rpm range. how ever some people like doing that. i wouldn't go to a 440. i would put an electric fuel pump next to the fuel tank. iam using a airtex ( carter ) e84070m on a garden tractor project. rig it so you can pump up the fuel before you start it. a spring return switch and a master switch. also get a holley 12-810 safety switch. also use only steel brake for routing the fuel line, ie use as small amount of hose as you can. this way when you hit hot weather it wont vapor lock.