My "New" Mustang

[70Mach1]

I just picked up and transported my "new" 70 Mach 1 850 miles and am ready to start work. I have a few questions. From the VIN I was able to tell that the car is a 1970 Mach 1 that came with a 351C 4v. There is some confusion over what engine and transmission are actually in my car. I was told by the previous owner that it is a 302 Boss engine. I have a lot of trouble believing this. The engine is mated to an auto trans and I was under the impression that a 302 Boss engine would not mate to an auto trans. Is there any way to tell for sure what the engine is? He also told me that the transmission (a 3 speed auto) is an FMX(???). What is an FMX. Have only ever heard of a C4 or C6. Again, is there any way to tell for sure what the tranmission is? Being a Chevy person originally, just recently converted , I am struggling here to gain some knowledge. Also, my dataplate is gone so I was wondering if there was any other way to determine what options my car had. It still has the 9" rear (woohoo) with 3.00 gears although it is a peg leg. Any help is greatly appreciated and I am sure I will be posting more questions in the future.

Thanks for helping this newly converted Ford driver.

[Shaggy]

First off do your heads look like big block Chevy heads if they do you have the C/M/boss heads Several things to look for on your heads on the top front there is a corner that stick out a little past the valve cover your heads will have a 4 cast there if they are 4-V heads. Look between your water pump and block if the timing cover is aluminum and about 1 1/2" thick you have the heads on a Windsor block if the timing cover is a 1/4" piece of plate you have the C/M block. Now the C block uses small block motor mounts and bellhousing . The M uses big block motor mounts and bellhousing. On the windsors look at the timing cover upper right where the water passage is there is a machined surface from that machined surface if the distance from the bottom of the head is about 1" then you have the 351W block if it right on top of it then you have the 289/302W block. All that said if my memory serves me right the FMX only had the small block bellhousing so don't worry about the M series block. The FMX was an iron case intermediate strength tranny the C-4 being the weak pass. car the FMX being in most small block hot rods and the C-6 being the strong truck tranny. (The tranny info is stock strengths the C-4 can be built to be much stronger than the FMX.)

[Shaggy]

First off do your heads look like big block Chevy heads if they do you have the C/M/boss heads Several things to look for on your heads on the top front there is a corner that stick out a little past the valve cover your heads will have a 4 cast there if they are 4-V heads. Look between your water pump and block if the timing cover is aluminum and about 1 1/2" thick you have the heads on a Windsor block if the timing cover is a 1/4" piece of plate you have the C/M block. Now the C block uses small block motor mounts and bellhousing . The M uses big block motor mounts and bellhousing. On the windsors look at the timing cover upper right where the water passage is there is a machined surface from that machined surface if the distance from the bottom of the head is about 1" then you have the 351W block if it right on top of it then you have the 289/302W block. All that said if my memory serves me right the FMX only had the small block bellhousing so don't worry about the M series block. The FMX was an iron case intermediate strength tranny the C-4 being the weak pass. car the FMX being in most small block hot rods and the C-6 being the strong truck tranny. (The tranny info is stock strengths the C-4 can be built to be much stronger than the FMX.)

[Clark Rodgers]

You might get lucky and find the original build sheets under the carpet.This is a long shot but this would give you all the information you would need.Don't forget the back seat carpet as well and if your restoring it you should be pulling this up anyways.
I have a 69 Sportsroof 351W FMX and I am happy with the performance of the transmission it has no problem barking the tires when it shifts gears!

[This message has been edited by Clark Rodgers (edited 05-25-99).]

[70Mach1]

Ok, Shaggy, I looked at the things you tolm and and aside from the heads I see a 1.5" aluminum timing chain cover and there is 1" between the bottom of the head and the machined surface. I take this to mean I have a 351W. My next question is about the heads. The passenger side head has a "1" where you said the "4" would be for 4v heads. The driver side head has a "13" in the same spot. Any ideas about these numbers. Thanks Again.

[Shaggy]

I don't know what those numbers are. on your exhuast are the bolt in a straight line or canted? if they are in a straight line they are Windsor heads.If you have the Clevland heads you have what is called a Clevor. Which is a Windsor block with Cleland heads.

[jhoffman]

I think the C4 is a great small block transmission. I have had a lot of them and if I could choose between the c4 and the fmx it would definelty be the c4 with a shift kit installed. the fmx I believe was built in Mexico. If you have your VIN number off the title or door, there is a woman in Michigan that has original window stickers for 69 and 70 mustangs I think she charges 30 dollars for them. Her name is Lois...something or another, her name is in all the mustang magazines take a look. It will be listed in there. In fact I think I saw it in this months Mustang Monthly. If I run across it again I will let you know. She will have all the info on your car.

[jhoffman]

And another thing I believe is you should have a number on your block, I know if it is a boss 302 it will have the G code in it.