Information and Parts list for the I-6 to V-8 swap

Last month I performed the legendary I-6 to V-8 engine swap. Going into the swap, I had a lot of questions, and found a lot of good information and advice here on this site. I tried to remember most of it, and have typed it up for all to see. Keep in mind though, that I am no profesional, and this is just what worked for me. And I probably left some stuff out. If you have any questions just ask 'em. Hope this helps somebody.


200 I-6 to 302 V-8
SWAP LIST

PARTS YOU WILL NEED

302 V-8
302 MAVERICK motor mounts
302 frame mounts
V-8 Engine cross-member
Double hump transmission cross-member
V-8 Power steering bracket
Longer Power Steering Hoses
V-8 Alternator bracket
V-8 Starter
250 I-6 or small block ford V-8 bell-housing
250 I-6 or 302 Maverick radiator (Although I got away with using the 200's radiator)
Fan Shroud (not necessary, but unless you are using an electric fan it will be missed)
V-8 Pulleys -Power steering/crankshaft/fan/water pump
Front Sump oil Pan

I-6 PARTS THAT CAN BE USED IN THE SWAP

Power Steering Pump
Alternator
C-4 transmission (any C-4 should work, as long as the bell- housing is changed to a V-8 bell-housing)
I-6 Throttle Cable

SOME (HOPEFULLY) HELPFUL ADVICE

When doing this swap, you CAN, I repeat, CAN retain the stock 6 cylinder springs. In keeping the I-6 springs, you car will sit lower in the front. I kept the I-6 springs in mine, and have NOT noticed the handling to be that bad. I DO recommend, however, that you take the car and have it aligned. This is strictly left up to you. Another thing that I did, was use my stock 200 ci I-6 radiator in the swap. I did have it re-cored, (which I would recommend that you do) and it works fine. I used a 160 degree thermostat, and I cruise at anywhere from 150 - 190 degrees at 70 and 80, depending on the weather. If you want to run cooler, use a bigger radiator or have an aluminum radiator built. I have also used two different fan setups on this engine, a 16 inch electric fan, and the block-type straight fan off of my 200 I-6. Both worked fine. I have the electric fan on a toggle switch, so I can continue cooling the radiator after killing the car. I DO NOT use both fans at once. I just tested both of them. Personally, I like the electric fan better as it has a built-in shroud, and can continue to run after switching the car off. As far as the transmission goes, I got one from Auto Zone for $430.00 with a 15 month unlimited mile warranty. I would recommend buying one or having yours rebuilt instead of just bolting the I-6 C-4 right on in there. It probably won’t last. It will work though with the V-8 bell-housing.


THIS REALLY CAN BE DONE !!!

It has been said that you could not have long-tube headers and retain the automatic shifter on the column. It can be done. I did it. What I will say is that the stock shift rod will have to be bent to fit from the selector on the transmission itself to the column shift lever on the firewall. It will just be trial and error, but if you keep trying, you will eventually get the angles bent right to fit around and through the headers. One thing though, I had to manufacture a drop-bracket for the power steering power cylinder because the shaft was rubbing on the header. I just cut a piece of iron and drilled two holes in it- one to bolt to the car, and the other to bolt to the power steering piece that was rubbing. This lowered the power cylinder about 1 ½ inches. Plenty to clear the header. This was basically all that it took to enable the use of headers with the column shift auto.



Please keep in mind, that these things worked for me, and should work for you. If I left out any parts, just put ‘em on in there. If anyone else has some advise on this swap, feel free to add. I’m sure that I left something (s) out, but I hope that this will help some of you who are wondering what it would take to do the swap. Keep in mind though, this stuff ain’t just gonna jump right in there. Be prepared to spend a little time, and effort, if not some money to do it right. It’s worth it though. Hope this helps – Country

 

Sorry about the bad pics

Better pictures (not much better, but a little bit) can be found if you search for the post called New Pictures, found in this Main Forum. Hopefully this week I will take some pictures with the digital camera. Country

 

I'm getting ready to do this swap soon. I have everything in the list. I just need to order my cam and grind valve reliefs in my flat top pistions.

Will the mustang double sump oil pan work? I figured it would but then I think I was something somewhere that made me think it wouldnt.

 

Double sump

Sorry, but the double sump pan will NOT work on a stck maverick frame. You will need to get a front sump pan. Sorry I left that out. I bought a chrome front sump oil pan off of ebay for about $50.00. The quality is very good, the only problem is that it is not notched for the dipstick. The dipstick will go, it is just VERY hard to pull in or out. Works though. It's a thought. Good Luck with the project, and if you have any more questions, just ask. Country

 

I too, am in the middle of a 302/c-4 swap (from '68 mustang), into a '70 maverick. I'm having one major problem. I got a dual hump trans crossmember from a '72 mav with a 302, column shift. The trans seems to be too high in the tunnel (i think), because,

A: the trans is binding on the mustang floor shifter.
B: the shift linkage binds on the tunnel reinfocement.

I did a similar swap years ago, the only difference being a single hump crossmember, and i had no trouble whatsoever.

any ideas??

 

Are you positive that it is a C-4 transmission? Just want to be sure. I'll ask around. Good Luck ! Preston

 

Ah...Just thought of something. I think I recall someone saying that a '70 model Mavericks tranny tunnel was narrower. I'll check on that too. Preston

 

70 maverick swap

From what I remember that is the problem. The floor on a70 is different than the rest of the mav's. Also so is the gas tank. good luck.

 

'70 mav tunnel

ok thanks for the tunnel info. i can deal with the width issue. now as for the crossmember, does anyone know the distance (height) between the plane of the two tunnel mounting holes down to the base where the trans mount studs go in?
this measures just under 2" on my crossmember. any info here would be helpful....i don't want to do any drastic cutting on my car. i'm new to this site and it is AWESOME! many thanks!

paul m.

 

'70 mav tunnel

also country mav, thanks, and yep, my trans is a c-4.

paul m.

 

On the 70' model the bolt hole on the drivers side is in a different location when using the double humper........if you are trying to mount the crossmember with the original hole (the hole that the I6 crossmember bolted up to) that is your problem.......now if I could only remember how high to drill a new hole.....also you have to cut on the crossmember........on the driver side to get it to go up to the point it needs to go to be level for the tranny.....

best tip I can give is to put the I6 crossmember back in, measure in all directions.....TWICE and then take it out and start cutting and drilling.

 

'70 mav tunnel

hello 5946,

thanks for the reply. my cars tunnel already had the higher hole on the drivers side.....yes i had to 'trim' that side of the double hump xmember. when all bolted up, the trans tailshaft binds against the bottom of the auto floorshifter. i think i will have to modify my crossmember IF it won't mess up the driveline angle. thanks again!

paul m.

 

I did a temp. 250 to 302 swap I used the 250 springs ( it don`t set lower the 250 & 302 springs must be the same :confused: ) , I used the 250 C4 tranny , starter , bellhousing , torque convertor, rad, and the single hump crosmember . I used a '82 302 so I had to get a front sump oil pan a new pick up tube and a set of exhaust manifolds I got it all for 40 bux from the junk yard . I had to get a 157 tooth 50 oz flexplate , motor mouts frame mounts and the cross brace too .

I`d say that doing a 250 to 302 swap is easier and cheaper than a 170 or 200 to 302 swap .

 

when todd did the swap (200 to 302) he wanted a floor shift for the c4. tunnel was too narrow for a maverick floor shifter. went with a b&n or m or whatever it is. thecable linkage is easier to deal with than the shift rod. never noticed how much narrower the 70 is... then looked at my 72 and WOW! huge difference.

 

todds swap

hey scott,

did not really want to go this route, but i guess B&Ms-r-us. THANKS!

paul m.