Intake question
Logistics Pro
Joined: Jul 2005
Posts: 4,217
Likes: 154
What accessories are you running?
The hole at lower left is for your temperature gauge/warning light sender - or for a heater hose as Christmas mentioned.
The one at lower right is maybe for some kind of intake air temperature sensor on cylinder #5's intake runner? You'll probably want to thread a plug into that - use anti-seize compound...
The hole at the top left runner, cylinder #4, looks to be the same thing.
But I also see holes in the center of your heads, which peek out above the manifold. Those will need to be blocked as well.
The hole at lower left is for your temperature gauge/warning light sender - or for a heater hose as Christmas mentioned.
The one at lower right is maybe for some kind of intake air temperature sensor on cylinder #5's intake runner? You'll probably want to thread a plug into that - use anti-seize compound...
The hole at the top left runner, cylinder #4, looks to be the same thing.
But I also see holes in the center of your heads, which peek out above the manifold. Those will need to be blocked as well.
Thread Starter
|
Mountain Pass
Joined: Jul 2020
Posts: 155
Likes: 7
What accessories are you running?
The hole at lower left is for your temperature gauge/warning light sender - or for a heater hose as Christmas mentioned.
The one at lower right is maybe for some kind of intake air temperature sensor on cylinder #5's intake runner? You'll probably want to thread a plug into that - use anti-seize compound...
The hole at the top left runner, cylinder #4, looks to be the same thing.
But I also see holes in the center of your heads, which peek out above the manifold. Those will need to be blocked as well.
The hole at lower left is for your temperature gauge/warning light sender - or for a heater hose as Christmas mentioned.
The one at lower right is maybe for some kind of intake air temperature sensor on cylinder #5's intake runner? You'll probably want to thread a plug into that - use anti-seize compound...
The hole at the top left runner, cylinder #4, looks to be the same thing.
But I also see holes in the center of your heads, which peek out above the manifold. Those will need to be blocked as well.
More Turbo
Joined: Mar 2019
Posts: 530
Likes: 89
When I still had my 351M in my 78 Bronco it had that intake on it. The back vacuum port had a vacuum tree installed in it for all of my vacuum accessories. The big one in the front left of your pic was plugged as was the small one on the front right. I later put a Holley Sniper on it and I plugged all of the intake ports and ran all of my vacuum lines through the Sniper.
Believe it or not, but the 351M/400 has a dry intake. The coolant temp sender actually goes into the block below the thermostat housing. You can also put it into the water pump if your pump has a port for it. I had two on my 351M when I had the Sniper on it, one for the Sniper and one for the factory gauge and those two locations are what I used.
Believe it or not, but the 351M/400 has a dry intake. The coolant temp sender actually goes into the block below the thermostat housing. You can also put it into the water pump if your pump has a port for it. I had two on my 351M when I had the Sniper on it, one for the Sniper and one for the factory gauge and those two locations are what I used.
Trending Topics
More Turbo
Joined: Mar 2019
Posts: 530
Likes: 89
Oh, and then that little one off to the right of the front right vacuum port should be a bolt hole for the coil bracket. That's where mine was anyway.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Laughing Gas
Joined: Apr 2016
Posts: 858
Likes: 118
From: Buffalo NY
Doosenberry is correct. The 335 engine (351c/m/400) intakes do not have coolant passing through them. The large hole near the thermostat housing is for emissions used on some engines. Plug it. The other 2 are vacuum ports. The small round holes in the heads are to relieve heat from the exhaust crossover. Do not block or fill them. .Brass hex drive plugs have a much cleaner look than the square head ones from plumbing stores. For some good info on 351M/400 engines go to; Bubba's M-Block Ford V8 Workshop
Thread Starter
|
Mountain Pass
Joined: Jul 2020
Posts: 155
Likes: 7
Doosenberry is correct. The 335 engine (351c/m/400) intakes do not have coolant passing through them. The large hole near the thermostat housing is for emissions used on some engines. Plug it. The other 2 are vacuum ports. The small round holes in the heads are to relieve heat from the exhaust crossover. Do not block or fill them. .Brass hex drive plugs have a much cleaner look than the square head ones from plumbing stores. For some good info on 351M/400 engines go to; Bubba's M-Block Ford V8 Workshop
Post Fiend
Joined: Feb 2008
Posts: 5,831
Likes: 121
From: St Albert, Alberta
The big hole on the front left of the DIST is the thematic injection connection. Just plug it off. All the other holes are vacuum sources.. Plug off the stuff you are not using with hex head recessed pipe plugs such as below. No point in using stuff that sticks up above the intake..
https://www.summitracing.com/parts/e...SABEgKeS_D_BwE
https://www.summitracing.com/parts/e...SABEgKeS_D_BwE
Thread Starter
|
Mountain Pass
Joined: Jul 2020
Posts: 155
Likes: 7
The big hole on the front left of the DIST is the thematic injection connection. Just plug it off. All the other holes are vacuum sources.. Plug off the stuff you are not using with hex head recessed pipe plugs such as below. No point in using stuff that sticks up above the intake..
https://www.summitracing.com/parts/e...SABEgKeS_D_BwE
https://www.summitracing.com/parts/e...SABEgKeS_D_BwE