Howdy Y'all


Well, I am looking to do a few upgrades to my 351M and figured I'd look for some input. I am currently running the stock EGR style manifold with the 2150-2V carburetor. I have been looking into the Edelbrock Performer intake and a 1406 600 CFM carburetor with an electric choke. Any of y'all out there running this combo? If so, what are your likes and dislikes on it? my engine is pretty much stock, the EGR components have been removed, and I am looking for better parts availability and drivability. my 2150 is no longer holding a tune, no matter what I do.


I have also looked into moving up in the ignition department as well. I currently have the Ford Dura-Spark II and have been reading up on the Davis Unified Ignition (DUI) HEI style ignition. Anyone running this distributor? There seems to be a lot of good to come from an HEI distributor. Cleaning up under the hood, cheaper parts, American made components, and getting rid of the resisted ignition for a full 12V one wire feed.


The intake and ignition upgrade are laying groundwork for a future fuel injection drop-in. The Carburetor allows me to keep the truck on the road in the mean time.

 

Ive run that combo on a few different trucks in the past, no problems. As far as the distibuter goe,s there is nothing wrong with the stock ignition it can support up to 350 horsepower easily.

 

No mention of exhaust upgrades. Id run headers and duals before or at the same time improve the intake side of the engine.

 

I've run that combo on many of my 400 equipped vehicles. It's a solid combo because the edelbrock carb is pretty much ready to go out of the box and has the adapters needed to work with our throttle linkage and such. However as HIO said, without some improvement to the exhaust, the gains you'd see from a manifold and carb won't be completely felt.

No comment on the ignition, but for what it's worth the DuraSpark II is not a bad system at all. My personal opinion is that if it works, leave it alone and spend the money you'd be saving on exhaust work.

​​​​​
​​

 

Agree with above .... though there are better cam set ups that will help. 351M has like 8 or 8.1 CR so don't go wild on overlap. Duals would help some .... or a good 2-1/2 to 3 inch single from the split back with a suitable muffler.
Many newer trucks have decent sized mufflers of stainless, sometimes found cheaply behind the local exhaust shop. Think "diesel" muffler.
Dura Spark II is good .... just carry a spare control unit. My OEM one only started to cut out intermittently last year .... like once in a rare while on a hot day. It's now my second back up.

My '77 351M / C-6 / 3.50 gearing / 31" rubber had since 1986 got a Performer 400 intake and Holley #1850 - 600 and it's Crane FB cam (like Edelbrock #2172) in the late '80s got steady 12 mpg on highway at under 63-62 mph couple trips to Ga and back years ago. Once I worked on jets and got it into low 14s on a camping trip down to Ga coast and up along OBX into Delaware and across Md. to Cumberland ..... but soon after getting home it burnt a valve .... so fattened them up when I fixed her. Lately have Edelbrock #1405 - 600cfm man choke that doesn't leak, but it needed a FPR set at 5.5 to work. Seems to get at least as good on gas mileage in drives over to Lynchburg or Roanoke, etc.

 

I installed that very setup on my 400 with stock exhaust manifolds and went from 8mpg to 11 in town, 12 on the highway.

Robert

 

On my 351m, I installed a Performer intake and a Holley 600 w/vacuum secondaries. Very good upgrade, made better by headers and dual exhaust

The big difference, for me, came with an RV cam and double-roller timing set (set straight-up).

 

Have a very similar setup, 351M with a Performer manifold and a 600cfm, manual choke - it also has headers, and I was told an RV cam (built by PO). Not 100% on the cam, it actually idles way too nice - use it to feed hay, and it will idle across a field in 4low with 3.55 gears. It's in a beat-to-snot F250 4x4 with a flatbed, and it's a sleeper - will flat-out smoke my other 78, also a 250 4x4, same gears, but with a box-stock 400.

 

I installed headers, dual exhaust, performer intake, MSD distributor, and FiTech Fuel Injection on my 78. Runs like a champ.

 

I am still running the stock 2 into 1 exhaust and have plans on putting a true dual exhaust in with high flow mufflers or glass packs. I am going to leave the stock manifolds though, I am not a fan of headers. I have had them on trucks in the past and they caused me trouble... cooking plug wires, starters, transmission fluid and so on. I may call it good by replacing the 2-1/4 inch pipe with 2-1/2....

 

so just an intake and carb swap got you better mileage?

 

I am looking real hard at the FiTech set-up. I bet it starts, runs, and idles great with that huh? Is the throttle response and gas mileage better since putting that on your truck? Did you use their sump kit or their return kit? It seems like a pretty straight forward install that can be done in a weekend... What are your likes/dislikes with the FiTech kit?

 

Eddy stuff is typical....nothing bad about it, it's just that for the same or less $, there are better components out there.....as mentioned above

 

Best upgrade for a 351m is a 400 crank and rods, fix the factory mistake! Short of going into the engine the eddy intake, a 4 barrel and exhaust will help. Forget about ignition at your level if everything is working with yours u won't see a gain. I run the Fitech and while I'm pleased it's not as self tuning as one would hope. My engine is fairly modified though. I imagine on a stock engine it very well may be bolt on and go. I may try it on the wife's '70 with a stock 360 and find out

 

First thing I would do is add 109 cubic inches.