351 (Levy 408) dropped motor mounts and air cleaner?

[silver_pilate]

Gordon is finishing up my motor and transmission this coming week, and I'm collecting a few things in anticipation of it coming in. The motor is a 408 (Dart 351 block) with Victor Jr. heads and intake and a QF 750 carb, and I got a video of it idling on a test stand yesterday. He recommends using dropped solid mounts to make things fit better and create a bit more room on top. Here's what I'm looking at:

https://lmr.com/item/LRS-6038DS/1979...d-Motor-Mounts

A few questions:

-I have always really liked the look of the oval Cobra air cleaners, but I'm worried I won't get enough airflow, and clearance may be an issue. Any recommendations on a route for the air cleaner? Will the oval Cobra cleaner fit (3" filter for flow?) or do I need a filter top cleaner to get enough airflow? Any specific recs or links would be much appreciated.

-With the solid dropped motor mounts and a TKO600, how's the alignment at the end of the transmission for pinion angle? Does anyone sell a spacer set, or do I need to wait until it's in, measure, and order a spacer then?

Any other thoughts or tips? Thanks.

--Nathan

[Jeff Kleiner]

I just made this reply on the other forum! The big question is what intake.

The various Edelbrock intakes for standard deck height 351 blocks stack up like so:

Performer RPM Air Gap #7581 has a carb pad height of 5.75" and RPM range of 1,500-6,500.

The Performer RPM #7181 has a pad height of 4.8" and the same 1,500-6,500 RPM range

The Performer #2181 has a pad height of 4.120" and RPM range of idle to 5,500.

If you're using an Performer RPM Air Gap #7581 intake you'll probably have issues with an oval filter touching the hood. I've gotten in 3 or 4 cars with the 351 block/Air Gap/Oval combination and here's what happens:



A 14" round filter with a drop base and Extreme top will clear and breathe better than the restrictive oval.



Depending on the oil pan being used lower/dropped mounts may result in it hanging below the frame rails.

On a related note while we're on the subject of intakes; some owners have found that the RPM Air Gap intake creates some drivability issues at low RPMs and changing to the lower profile Performer solved both the hood clearance problem and also resulted in a happier engine on the street. Just something to think about...

Jeff

[mike223]

The motor is a 408 (Dart 351 block) with Victor Jr. heads and intake and a QF 750 carb...

<snip>

A few questions:

-I have always really liked the look of the oval Cobra air cleaners, but I'm worried I won't get enough airflow, and clearance may be an issue. Any recommendations on a route for the air cleaner? Will the oval Cobra cleaner fit (3" filter for flow?) or do I need a filter top cleaner to get enough airflow? Any specific recs or links would be much appreciated.

Any other thoughts or tips? Thanks.

Nathan,

I guarantee you can put on the oval air cleaner with the 1.75" tall air filter and you will soon going to find out that you are completely traction limited to 100mph.

Probably at half throttle in third gear (it depends on gearing - 3.55 will do it).

How much more airflow do you think you need?


Sorry, no advice on fitment.

[silver_pilate]

Nathan,

I guarantee you can put on the oval air cleaner with the 1.75" tall air filter and you will soon going to find out that you are completely traction limited to 100mph.

Probably at half throttle in third gear (it depends on gearing - 3.55 will do it).

How much more airflow do you think you need?


Sorry, no advice on fitment.

Thanks Jeff and Mike. I went ahead and ordered the 14" round for now and may try the oval later on when I know how the motor sits. Gordon chimed in on the other site and corrected that it's actually an performer RPM intake, so not quite as tall, giving me a bit of room to play with.

Mike, I've always wanted a car that has more horsepower than is usable. 550+ flywheel hp in this car should do it, I think.

[GoDadGo]

If you want it to breathe on the top end and be as low as you can go then maybe the Torquer II would be a good option at 4.15" for the carb pad.
Since you've got a rather large engine your bottom end torque really won't be an issue with a single plane manifold.
The operation range is 2,500 - 6,500 RPM's and the large displacement will calm things down.
The big question is will the intake ports properly match up or not?

https://www.summitracing.com/parts/e...view/make/ford

Good Luck From The Dark-Dart Side!

[mike223]

Mike, I've always wanted a car that has more horsepower than is usable. 550+ flywheel hp in this car should do it, I think.

I tried to build 500hp / 500ftlbs torque (same reasons).

Best guess at this point ~465hp/ 550ftlbs.

I am more convinced than ever that the "sweet spot" is around 400/400.

It just gets harder to drive it "well" over that - no faster to 100, just more complicated to get there as fast.


Good luck, best to start out "terrified" of it (you really should be),

Mike

[GoDadGo]

I am more convinced than ever that the "sweet spot" is around 400/400.

Ditto From The Dark-Dart Side!