200-250 motor mount locations

Curseoftheblade

Active member
Hey all,

I've been planning a 250 swap into my 1966 Mustang for a while now. I know pretty much everything that needs to be changed or modified. To fit the 250 under the hood without making a scoop, 250 engine mounts are needed. I'm curious where the holes for them have to be drilled in perspective to where the 200 mounts are. Is the 250 even any wider than the 200? If not, would i just be able to bolt the 250 mounts where the 200 mounts are currently? Thanks a bunch.

Connor
 
Thank you for the link. I have read that multiple times when researching for this swap. It doesn't describe the new bolt hole locations any, just that they are needed. The engine is 1.5" wider about. Does that mean the mounts for the 250 need to be 1.5" wider than the 200 mount (between the two of them: 0.75" per) or do the 250 mounts use the same location as the mounts already and account for the increased width, just requiring drilling for larger bolt holes or something?

I guess i'm asking: do the 250 mounts go in the same spots as the 200 mounts and the holes just need to be drilled larger? Or do the 250 mounts need to be shifted entirely...if so, does anyone know where the holes should be drilled for the 250 mounts in comparison to the existing 200 mount holes?

Thanks
 
The front 2 mount holes in a 200 and a 250 are the same distance from the rear of the block.
The front 2 mount holes are the same distance above the oil pan line.
*if* you are going to use stock motor mounts you need to drill 2 new holes 1" higher than the stock 200 motor mount holes, that will allow the motor to sit 1" lower in the engine bay.
The other part of the equation is the frame side brackets, you will need to leave the bolts/nuts loose until you have the motor sat down in place.

The motor will still sit a bit higher than a 200
And without setting the motor rearward somehow, it will be longer in the front (less radiator space) you may have to find a slim fan option (flex fan) or mount an electric fan on the front of the radiator in a pusher configuration.
What type of vehicle are you working on?

Good luck!
-ron
 
the torquey' 250 is a great upgrade and with complementary drivetrain gearing can enable modern driving speeds with ease. The 250 can use OEM or performance SBF V8 clutch & trannys. Since the 250 was never offered in a 66', I would be cautious bout lowering the engine mounts until you test-fit . The low mount starter and wider bell can interfere with the early car steering and under-engine bar if it has one.

from CI cob-web site:

Height, width, and length need to be considered. The 250ci is 1.66” taller than the 200ci. On early Mustangs this poses a hood clearance problem. The original early air cleaner is too tall to clear the hood. However a Maverick or Late (79-82) Mustang air cleaner is lower and will provide needed clearance. Because the carburetor is now higher, the throttle linkage also needs to be raised either by bending the linkage or extending it. The original lines from the 200ci fuel pump and the vacuum lines from the carburetor will also be too short and new ones need be made..The 250ci is approximately 1.5” wider at the motor mount bosses. The original Mustang mounts can be used, but they will place the engine higher in the compartment because of the way the brackets are angled. Elongating the bolt holes in the engine mounts to allow the engine to drop slightly will help, but the proper solution is to use Maverick 250ci mounts and brackets. The Maverick mounts are designed differently and will require new bolt holes in the frame.

I was able to re-drill the early (61) right angle engine mounts @ 3/4" each side and then worked out the 250's interference issues for a much more drivable car.

'pinned' for the torque of 250 vs original 170:. . .

have fun
 
CoupeBoy":5un06xzw said:
The front 2 mount holes in a 200 and a 250 are the same distance from the rear of the block.
The front 2 mount holes are the same distance above the oil pan line.
*if* you are going to use stock motor mounts you need to drill 2 new holes 1" higher than the stock 200 motor mount holes, that will allow the motor to sit 1" lower in the engine bay.
The other part of the equation is the frame side brackets, you will need to leave the bolts/nuts loose until you have the motor sat down in place.

The motor will still sit a bit higher than a 200
And without setting the motor rearward somehow, it will be longer in the front (less radiator space) you may have to find a slim fan option (flex fan) or mount an electric fan on the front of the radiator in a pusher configuration.
What type of vehicle are you working on?

Good luck!
-ron

I have acquired 250 motor mounts from a Maverick that had a 250. If i bolt them in to the pre=existing 200 motor mount holes, will the engine fit? Or will i have to drill new holes in different locations for the 250 mounts to work? I understand the engine will extend further forward and may pose a fan problem. The car is a 1966 Mustang.
 
powerband":wf7g6pl7 said:
the torquey' 250 is a great upgrade and with complementary drivetrain gearing can enable modern driving speeds with ease. The 250 can use OEM or performance SBF V8 clutch & trannys. Since the 250 was never offered in a 66', I would be cautious bout lowering the engine mounts until you test-fit . The low mount starter and wider bell can interfere with the early car steering and under-engine bar if it has one.

from CI cob-web site:

Height, width, and length need to be considered. The 250ci is 1.66” taller than the 200ci. On early Mustangs this poses a hood clearance problem. The original early air cleaner is too tall to clear the hood. However a Maverick or Late (79-82) Mustang air cleaner is lower and will provide needed clearance. Because the carburetor is now higher, the throttle linkage also needs to be raised either by bending the linkage or extending it. The original lines from the 200ci fuel pump and the vacuum lines from the carburetor will also be too short and new ones need be made..The 250ci is approximately 1.5” wider at the motor mount bosses. The original Mustang mounts can be used, but they will place the engine higher in the compartment because of the way the brackets are angled. Elongating the bolt holes in the engine mounts to allow the engine to drop slightly will help, but the proper solution is to use Maverick 250ci mounts and brackets. The Maverick mounts are designed differently and will require new bolt holes in the frame.

I was able to re-drill the early (61) right angle engine mounts @ 3/4" each side and then worked out the 250's interference issues for a much more drivable car.

'pinned' for the torque of 250 vs original 170:. . .

have fun

I'll be using 250 motor mounts from a Maverick with a 250. These should drop the engine enough for hood clearance. The CI page says they will require new holes in the frame. Do you know the change for the new bolt holes in comparison to where the original 200 mounts are? Otherwise, what did you do with the existing 200 mounts to fit the 250 in your application?
 
How much of the motor mount?
There have been people who used the whole motor mount from engine to uni-body. According to the tech article referenced earlier..
The 250ci is approximately 1.5” wider at the motor mount bosses. The original Mustang mounts can be used, but they will place the engine higher in the compartment because of the way the brackets are angled. Elongating the bolt holes in the engine mounts to allow the engine to drop slightly will help, but the proper solution is to use Maverick 250ci mounts and brackets. The Maverick mounts are designed differently and will require new bolt holes in the frame.
 
... using 250 motor mounts from a Maverick with a 250. These should drop the engine enough for hood clearance. The CI page says they will require new holes in the frame. Do you know the change for the new bolt holes in comparison to where the original 200 mounts are? Otherwise, what did you do with the existing 200 mounts to fit the 250 in your application?

the existing '61 frame brackets were able to to accommodate the additional @ 3/4" width each side of the 250 with some minor trimming. The early rubber mounts were 90 degree so simply re-drilled/moved them over on the frame brackets for the wider block. The '61 had no problem with hood clearance but I have a Maverick and the 250 needs a lot of thought to fit a carburetor and air cleaner much less turbo under hood. If you look at the approximate height of the top of the shocks you can see later Mustang and Maverick had much lower fender/hood lines comparatively.

You need some specific info on the 66/250 swap or figure on the width and height differences and test-fit first.

have fun

 
can't use the hood scoop because I need the windshield to flip down getting under low tree branches.
It will B a several stage process inc bolting the towers/mounts on the motor, lowering it in, marking the holes, taking it out, 'sloting' the bolt holes, placing towers in the rig, lowering the motor w/ mounts onto them, bolting again. Trying a hunk'a clay on carb to see how it gets squished by the hood...
I may skip the last step if I see the low rise carb/ac R low enuff on a glance from the side, but doubt that.
I'll post again (C if Perry has a 'stickie' function on the new site 2 leave this once'n 4 ALL) the following, not all apply as the list is 'truck' oriented, still a consideration for some:
* Body lift,
* suspension lift (yes, will help in some cases)
* slot mounts
* hood scoop
* Maverick mounts (?late '70s?)
* all the air cleaner tricks ('cold air', drop base a/c, remote, etc)
* direct mount carb
* low rise carbs (RBS, Autolite)
* mill head for carb (direct mount)

Good luck, keep us informed. If U come up w/any more let us know...
 
Thank you all. Yes i have motor mounts and brackets from a 75-76 maverick that had a 250. Sounds like i'll just have to measure /mark/measure again to find where the motor mount holes need to be drilled. Should all be happening next week. Worst case scenario it keeps the 200 for now. We'll see if i reply with any last minute questions. Any final advice/comments/opinions/etc?
 
IIRC no measuring is required.
The mounts will bolt up to one or two of the existing holes, and then you simply drill the rest where the frame side bracket ends up after dropping the engine in.

yes you can put the brackets onto the body and drop the motor in with only a single bolt in the frame side.... but don't drive it like that. :rolflmao:
 
Thanks a ton! That's what i was looking for. That or numbers. I apologize to anyone if they mentioned that but i didn't register it in my head.
 
Thanks to everyone!

image.jpg
 
hey how did the engine fit? I just picked up a 69 250 and want to swap it for my 200 in my 65 mustang. Did you get yours to fit on the original 200 mounts and brackets? Also I have a c4 tranny behind it. I know I need a different torque converter and bell housing, but can I still use the original flex plate? do I need a different starter? any help would be great here
 
You cannot use the 200 flex plate.
On the 200 the flex plate is something like a 4 pointed star and it bolts to the torque converter. And the torque converter had the starter ring gear welded to it.

On a 250 (240/300/SBF) the flex plate is round and the starter ring gear is welded to the flex plate not the torque converter.

And you need a different starter. The 200 uses a 3 bolt type, whereas the 250 uses a 2 bolt.
 
doogie":91289r2k said:
which flexplate would I use with the 250? the 157 teeth or the 164 teeth>

that depends on what bell housing you are going to use. you need to match the flexplate to the bell housing.
 
Curseoftheblade":3meilrxk said:
You need to use a smf V8 bellhousing and torque converter for the 250

Aren't there at least 2 SBF (250, 289, 300, 302, 5.0, 351, 400) bells?
 
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