Carburetor spacer?

JoColtrane · Jun 7, 2023

Hello,

351c 2bbl H code. Saw some conflicting info on the following so was hoping someone could clarify for me. Pulled my carburetor and noticed that there were two gaskets.

No spacer so here's my questions.

Did all 71, 72, 73's come with carb spacers or are there a certain engine/carb combinations that came with spacers?

Do the two gaskets indicate that my car once had a spacer?

Why does the bottom gasket have the other 4 cut outs and/or what purpose do they serve? (It's not in the rebuild kit?

With no spacer do I need or should I have two gaskets (apparently it's been working up until now) or do I just out the one on?

If my carb has a egr port does that mean it's not a stock '71 carb?

If I added a spacer w/egr do I block off the port on the carb or just get non-egr spacer?

AJ

Hemikiller · Jun 7, 2023

EGR was only used on '73 models. It had a spacer with the valve attached, it was not ported through the carb.

The 351C, to my knowledge, never used a spacer 70-72. The large port on your carb should be for the PCV, please post a pic. Also, look on the side of the driver's front mounting lug for a stamped identification number.

The correct gasket is the Felpro 60101. I personally would run two, as a way to keep heat out of the carb.

https://www.rockauto.com/en/moreinfo.php?pk=120964&cc=1132692&pt=10024&jsn=1374&jsn=1374

RC92234 · Jun 8, 2023

The curved cutouts are for the EGR channel, unique to '73.

It's curious you had two gaskets. The spacer on my '73 351C q code was in bad shape and came off in pieces (and was nearly burned through over the EGR channel) but it once was a one piece gasket. I replaced it with a perfect fit NOS piece found on eBay when I replaced the carburetor (original 4300D replaced with a matching spread bore 4360 from a 77 Lincoln). Still finagling with two things: the new choke and the different position of the EGR port (currently just capped), but the improvement with the new carb was outstanding.

Yes, I would have had the original 4300D rebuilt to maintain originality but it was too far gone.

Spike Morelli · Jun 8, 2023

My '71 Mach 1 "H" code is all stock. The correct gasket to use here is the one on the right, with the stainless steel heat shielding. The cars were produced with iron intake manifolds which had exhaust-crossover heat channeled under the carb, to an open trough going around the venturis. The gasket with the stainless steel sandwich is a heat barrier, so the exhaust gasses don't burn up the underside of the carb. This is the ONLY gasket to be used in this case. Sure, you may see some people tapping the exhaust feed holes in the stock manifold, and installing pipe plugs, to keep heat away from the carb, but, in everyday useage, or cool climates, you need this to help atomize properly, or so, says the manual. The openings in the factory cast iron manifolds commonly get clogged with carbon and become useless with time. Yours may well be fairly clogged. I make sure, any time I would have my carb off, that I drill out any carbon ( using a vacuum to keep carbon from just going into the crossover). Aftermarket aluminum performance manifolds will not have carb heat designed into them, and isn't preferred anyway, if higher performance is on your radar, but in stock 2-barrel form, you are likely to gain zero, from blocking the passage on purpose. The gasket on the left is for 2-barrel applications where there is not an under-carb heat channel. There is no EGR on '71 "H" codes. PCV, (positive crankcase ventilation ),is plumbed from the PCV valve in the filler cap on the driver's side valve cover, to the rear base nipple on the factory 2v carb.

mrgmhale · Jun 9, 2023

A quick aside, while reading the earlier posts in this thread I thought back when I used to work on these 70s and 80s Fords (to include Mustangs of course) at a Ford dealership in SoCal, I often found the carb base plate gasket material to have been baked onto the spacer plate, to the bottom plate of the carb, to the intake manifold, etc. It was such a PITA to get all of the offending gasket material removed when working on those cars. Sometimes the gasket material was a paper/asbestos material that covered an inner foil piece that was otherwise fairly flexible. Still, hard to get off at times - often in fact. Then one lucky day our Mac Tool guy came around and showed me a new pneumatic gasket scraper! Wow! What a time saver. But, I had to be careful with the softer metal used for the carb base and spacer plates, as the cutting edge could mar the softer metals parts very quickly.

Anyway, when I retired the other year, and began to work on the pony cars acquired after I retired, one of the first things I purchased was a pneumatic gasket scraper, which worked out great for a water pump replacement on our 73 Mustang 302. Hopefully someone will find this info to be useful.

https://www.harborfreight.com/6-piece-pneumatic-scraper-kit-95826.html