Can you please help me out. Need to order a Mechanical Fuel Pump from Summit. Do you know which one would fit my 400 -77 (4x4, aut, no AC)
Thanks!
https://www.summitracing.com/int/parts/crt-m6882
https://www.summitracing.com/int/parts/crt-m6978

 

M6978 specifically says that it fits 4x4 models. I would assume that one .

 

Thanks Jklnhyd.
I didn't notice M6978 was for 4x4. I am still not sure because when looking at applications it says 78-79. Also tried to look at inlet and outlet sizes but cant really see any differences.

 

Before you order from summit rock auto has the same carter pump for $13 if you go with the 6882.
https://www.rockauto.com/en/catalog/...fuel+pump,6256

I know I've used the 6978 on my 79 F250 4wd.

 

Thanks! That's very cheap!!! I am still not sure which to choose. I dont know the differences between the two.

 

The only difference I can see is the inlet and outlet orientation, one has the inlet on the left and the other is on the right and they face different directions. All the specs on those two links are the same. They'll both physically fit your 400. If it's any help, I looked up mechanical fuel pumps on summit for my 78 Bronco with a 351M (same block as the 400) and it pulls up the m6978. I replaced mine on my Bronco not too long ago with one from an auto parts store and it looks the same as that one.

 

This one is from a different supplier, but has the same part number for the pump, 6978. It says it'll fit 4x4 '77's. I would assume the carter would work or any other 6978, but then again! I would just keep second guessing yourself until you don't buy one at all, it'll save you money.

https://www.summitracing.com/parts/a...977/make/ford/

 

According to your specs and rockauto. The carter M6882 or Airtex 60007 are the pumps you want. The other two specify rwd. And according to ND, your truck would have had one of those from the factory anyway

 

1977 F100/350 2WD & 1977 F150/250 4WD 351M/400 use the same fuel pump. It was also used on cars:

D7SZ-9350-C (replaced D6AZ-9350-B; D7SZ-9350-B & D7TZ-9350-A) .. 351M/400 Fuel Pump / Obsolete

1977 F100 2WD / 1977 F150/250 2WD/4WD & F350 / 1978 F150/250 2WD & F350.

1976 LTD/Grand Marquis/Torino / 1977/78 LTD/Grand Marquis/LTD II(not an LTD!)/Thunderbird/Cougar/Ranchero / 1979 Thunderbird/Cougar.

Note: 1978/79 F150/250 4WD/Bronco & 1979 F350 4WD 351M/400 use a different fuel pump: D8TZ-9350-B

 

Thank you so much everyone!! I will order the M6882 from RA.

 

Hi!
I just want to confirm your information about my Fuel Pump. I took a Picture of the Pump yesterday and it look exactly like the one you suggested (M6882).
The inlet (hose barb) and the outlet (threads) are at the same places. it's probably 41 years old and I can read "MADE IN U.S.A" on the Pump.
Almost a shame to replace it for an asian Pump! Thanks a lot!!!

 

Some carters area still made in USA I believe. I know the one I out on my FE was but can't say on the other 2.

 

D8TZ-B = 6978; D7SZ-C = 6882