Engine lowering options?

[Len69Coupe 33]

So it turns out my hood is contacting my engine in 3 places. The worse being the front intake bolt, which has left a slight indention on my hood from contact. I could remove the intake spacer and that would fix all 3 issues, but could cause clearance issues elsewhere. Trying to get answer on removing the spacer is kind of like asking which oil is best, you get 50 different answers on if it really does anything. 

I thought I read that convertible motor mounts are a little lower. I've searched and I can't find anything that says there is a difference in motor mounts, other than small block and big block mounts. Unless I'm missing something I can't find any site that breaks out the convertible mounts from other mounts. Anyone know about the convertible motor mounts?

I have seen the adjustable motor mounts offered and they could be an option. I just hate to spend that much on motor mounts.

Last option would be to grind the intake bolt down some to see if it would clear. The other 2 spots hit the supports on the hood and could possibly be clearanced with a BFH. I'd hate to do that and it not turn out right.

 

[jmlay 80]

I would say you have your options covered.

These links pretty much sum it up the differences in motor mounts.:

https://www.428cobrajet.org/id-motor-mount-support-bracket

https://www.vintage-mustang.com/threads/66-convertible-motor-mounts.949169/#post-7809705

[Len69Coupe 33]

Thanks jmlay. So just so I understand this, the Convertible mounts are the same as the all 67 and 68-70 Big Block mounts? So how far will these mounts drop the engine?

 

Gee whiz question for added points; why did the Convertible need a lowered engine?

[EastYorkStang 63]

I have heard that about Fox body convertibles. Nothing about our years. Nor have I seen any different part numbers for each model...

[Len69Coupe 33]

Maybe what I read was about Fox bodies. The links jmlay posted do say that the convertibles and Big Blocks had a different mount that lowered the engine. That's if I'm reading that information correctly.

[det0326 179]

Just be careful if u use lowering mounts. If your car is lowered any by changing spring rates or lowering spindles etc then u lower the engine also sometimes the pinion and driveshaft angle can get into a twilight zone.  That is originally the transmission tail shaft is higher than the pinion shaft but in lowering this and that u can cause these to swap. Then if u have any driveline vibrations it is sometimes hard to correct.

[det0326 179]

one solution may be to see if u can find some socket head flat head bolts and counter sink the holes so that the bolt heads will be flush with plenum. I also seem to remember that there is an after market plenum that might set a little lower.  

[Len69Coupe 33]

Thanks. I was wondering about driveline angles also. 

Easiest option at this point is to remove the spacer and see how everything fits.

[jmlay 80]

The links I provided describe a change in angles to address harmonics and vibration. Installed hight was the same.

[RPM 1,190]

Be careful what you wish for. I made the mistake of lowering the 351W to fit my 428 shaker air cleaner. The motor drop was only the first mod I had to make. 

• The stock engine crossmember doesn't allow much of an engine drop, so I had to make a different engine crossmember. 

• I modified the tranny crossmember to match the engine drop, to avoid vibrations. 

• I had to use an electrical fan as the stock fan interfered with the radiator hose.

• A bigger alternator was needed to handle the electrical fan.

• Fan belt slippage from the bigger alternator had me switch to a serpentine belt. 

That's just of the top of my head, there could be more mods I had to do. 

 

[69RavenConv 286]

On 4/1/2022 at 11:35 AM, Len69Coupe said:

Thanks jmlay. So just so I understand this, the Convertible mounts are the same as the all 67 and 68-70 Big Block mounts? So how far will these mounts drop the engine?

 

Gee whiz question for added points; why did the Convertible need a lowered engine?

I have a hazy memory of scrounging my junk pile for my original convertible mounts when I discovered the new repop replacements didn't match. This was 30+ years ago so I could be completely imagining this. I think the VMF thread link above covers it - they sit at a different angle but don't lower the engine. 

 

 

[Len69Coupe 33]

OK, I misunderstood the links then. I thought it was showing a different hole in the mounts that would lower the engine. So that's off the table. I sure don't want to open a can of worms with driveline vibrations and other issues. 

Simplest fix at this point is removing the one-inch intake spacer. Hopefully that won't cause clearance issues elsewhere.

I would try different bolts, but the hood support would still be hitting the air filter tube on the right side.

Thanks everyone :)

[Mach1 Driver 560]

11 hours ago, RPM said:

Be careful what you wish for. I made the mistake of lowering the 351W to fit my 428 shaker air cleaner. The motor drop was only the first mod I had to make. 

• The stock engine crossmember doesn't allow much of an engine drop, so I had to make a different engine crossmember. 

• I modified the tranny crossmember to match the engine drop, to avoid vibrations. 

• I had to use an electrical fan as the stock fan interfered with the radiator hose.

• A bigger alternator was needed to handle the electrical fan.

• Fan belt slippage from the bigger alternator had me switch to a serpentine belt. 

That's just of the top of my head, there could be more mods I had to do. 

 

...and the beat goes on....

[Vicfreg 771]

My convertible stock mounts and mounting location for my small block look to be identical to the replacement mounts I originally got.  I tried lowered mounts to help with some header clearance, but like Bob, there were many little things that caused me to abandon that.  Number one reason was interference with my header and steering box.  

If anything, the convertibles would be slightly higher, not lower, as they have the mounting plate that connects the floor pans, and with a stock install, there is not much clearance between the driveshaft and that plate.

I would take a 1/2 inch off of that spacer plate if you could.  I don't recall my 5.0 having one of them.  Just check the clearance between the intake down turn and the drivers side valve cover before you do that.

[Len69Coupe 33]

I ended up getting a new spacer plate that is 1/2". The old one was 1", so I should have plenty of room between the intake and the hood now. 

Vicfreg, you are correct, with no spacer the intake would hit the left side valve cover.

Thanks for everyone's help.