M38 fuel pump spacer

[wesk]

JimBob tried to post this using the email admin address so I copied it here for him.

Does the M38 require a spacer between the fuel pump and the block?  Mine does not have one and seams to work ok, I checked fuel pump pressure  4lbs. What should I do?<br />



JIMBOB

[wesk]

Hello JimBob,

If you have the military dual vac/fuel pump you need to use the 9/16" thick spacer. The civvy pumps do not need it.

Two problems will show up sooner or later when running the military pump without a spacer.

1-Incorrect fuel pressure. Usually too high.

2-Increased wear rate on fuel pump drive cam on the crank.

The M38's original carb needs a 4.0 to 5.25 PSI operating pressure.

[jimbob]

Thanks for info. Wes

Jim