Best 70's Dodge Chassis for parts availability

[RickBright]

 I am new to the forum, have owned and restored a '73 Barth, several vintage travel trailers and presently have a '59 4104 GM conversion. My question is what Dodge motor home chassis with the 5 lug 19.5 wheels/bolt pattern would be the best as far as brake/chassis system reliability and parts availability be?

  If you were looking to buy a 70's Dodge chassis with the 5 lug on 8" 19.5 wheels is there a best/ better/worse breakdown of years and chassis models as far as the brake/chassis system reliability and part availability goes?

I am looking at a 1975 M500 front disk rear drum with the dual frame mounted booster system.  I have a 1972 Superior (drum drum) with the M375 Chassis with I believe the same booster system. I want something with 19.5 5 lug  as I have a set of new 19.5 Budd wheels and tires.

Just throwing this out hope it makes sense. I know not many people buy a motor home based on what wheels/tires they have on hand but this is my story and I am stickin to it.

Thanks in advance!
Rick

[DaveVA78Chieftain]

For parts availability, you would be better off converting to a 77 - 80 hydroboost based system.  M400 chassis used 17.5" rims.  M500 and M600 used 19.5" rims.

Dave

[RickBright]

 Can I convert the stock 1975 M500 vacuum hydro-vac master cylinder and twin boosters to a 77-80 fluid hydro boost system without changing the axles/hubs out? If so problem solved...I like the looks of the earlier Motor Homes just not so crazy about the hydro-vac boosters. Has anyone done this?  Or am I being too critical of the twin hydro-vac system?

Dave I have been to your site great work looks like you put a lot of time and effort into it...Thanks.

Rick

[DaveVA78Chieftain]

The wheels and hubs are the same for 75 up.  You would have to replace the Master cylinder, add the hydroboost unit, and all the power steering hoses.  Google hydroboost for basic system information.   Has been used on many diesel vehicles because it does not require vacuum.
Your to posts contradict each other so I take it you are looking a different possibilities.  To use the 19.5" rims you will have to change out hubs / axles.  My 77 M400 chassis uses hydroboost with 17.5" rims.  Dodge migrated to hydroboost on the M300 in 78 if memory serves me correctly. 

Dave