1970 200 vs. 1980 200

The valve guides in the 200 in my '72 Maverick seem to be getting pretty worn lately, and the compression is uneven. The engine came out of a '70 Maverick originally and is relatively low mileage, but I think the unleaded gas mixed with the 70+ miles a day I drive on the highway are taking their toll on the head. My C4 is starting to slip and leaking from about every seal as well. My brother recently picked up a 1980 Capri for parts that has a great running 200 and SROD 4 speed. So I'm trying to decide, should I swap the whole 200/SROD out of the Capri into my car, or just put the '80 head onto my '70 bottom end, and swap the C4 out for the SROD. What are the differences between the '70 and '80 engine?

Thanks.

rebuilding a c4 is fairly cheap considering u can find rebuilt kits on ebay for about a hundred bucks or so. im not sure about the crossmember, but take a measuring tape and measure from the motor mount bolts to the crossmember and vice versa for each engine, if the motor mounts look alike itll fit. but other tha that a 1970 engine isnt as powerful as a 1980, the 1970 may have a smaller log manifold. and the 1970 doesnt have the same starter location nor does it have the DUAL BELL housing bolt pattern that the 1980 does. i am rebuilding my 1980 mustang 200 and on the bellhousing flange there are 2 different patterns for bellhousings. Id do some checking to see if the 4 speed bolts to it if so go with the 1980. youll fell the difference. oh and BTW the 1980 mustang has a holley 1946 carb which is rated at 195cfm. which is a bit more than the 1970 200 has on it. measure and do your homework it should lay in there nicely. and have a bit more umff.

sctty1986":htjhnhqw said:

rebuilding a c4 is fairly cheap considering u can find rebuilt kits on ebay for about a hundred bucks or so. im not sure about the crossmember, but take a measuring tape and measure from the motor mount bolts to the crossmember and vice versa for each engine, if the motor mounts look alike itll fit. but other tha that a 1970 engine isnt as powerful as a 1980, the 1970 may have a smaller log manifold. and the 1970 doesnt have the same starter location nor does it have the DUAL BELL housing bolt pattern that the 1980 does. i am rebuilding my 1980 mustang 200 and on the bellhousing flange there are 2 different patterns for bellhousings. Id do some checking to see if the 4 speed bolts to it if so go with the 1980. youll fell the difference. oh and BTW the 1980 mustang has a holley 1946 carb which is rated at 195cfm. which is a bit more than the 1970 200 has on it. measure and do your homework it should lay in there nicely. and have a bit more umff.

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i thought 81 is the first year for the lower starter.a 72 block has the duel bolt pattern.id use the whole 1980 engine if the starter is in the same place.it will bolt in.id decide if i liked shifting gears before i decided to swap in the manual.im swapping in a c4.either war use the 1980 head.

If I wanted to rebuild the C4, I wouldn't have said I'm swapping in the SROD. In 127,000 total daily driven miles, I've gone through four C4's. I'd pay someone 100 bucks to chuck a C4 in a scrap dumpster. I'm done with them. Fitting the motor in is no problem, I already know I'll need to swap the oil pan and motor mounts. The manifold is of no concern to me, I have a header on the car and a Rochester carb, both of which will stay. I simply want to know what the internal differences are in the short block. I've heard the 1980 timing set and cam isn't as good?

Howdy Jamie and All:

The differences will be minor. The '80 may or may not have a different front pulley assembly than on the front of your '70 engine. The '70 is already down on advertized CR @ 8.8:1- the '80 is rated at a fairly tru 8:1. The bell housing and the SROD trans is the big difference on the back side. THe bell is unique to the SROD trans and so is the tranny mount. The difference in cam timing is in the cam, itself. All 200 timing gears are the same. The cam is advanced so that power and torque comes in sooner and lower in the rpm range. The '80 cam has prettly good stock lift at .372" as the valves as compared to the '70 cam at .348" lift. Front clearance between the fan and the radiator, motor mounts, tranny mount, and modifying the driveshaft will be the critical issues on the swap.

If the '80 engine is tight and clean running, I'd be inclined to swap first and decide what else might be needed later. More CR would be a no brainer for mileage and power. When the time comes a performance valve job and a straight up performance cam will really open your eyes, slacken your jaw and peg your smile meter!! What rear gear ratio is in your car?

On your '70 engine the oil is likely from the valve guide seals rather than the guides themselves. When your pull it check the seals. I'm betting their chunking. But, with your daily driving the OD trans will be a godsend. IIWIYS, I'd be making plans to do a complete swap. The ignition system alone is a bonus. The '80 will have a Holley #1946 carb, which is not my favorite, (I know, some of you like them). If you have a good running carb on the '70 is should be a direct swap. I'm not familiar with a Rochester carb on a '70 200. A '70 200 should have a Carter YF.

Keep us posted on your choice and your progress.

Enjoy!!!

Adios, David

Thanks David, exactly what I was looking for. I actually replaced the valve seals back in 2006 before I dropped the engine in (I had a beat to death '74 250 in it for a while prior), but that's been over 90,000 miles ago, so who knows, may need it again. The Rochester BC came off an old Chevy, I like it because it's very simple, I can rebuild the whole carb in 15 minutes with a flat head and needle nose pliers, and it's dead reliable, great drivability and never vapor locks. The car also has MSD ignition with a Duraspark II distributor, a header, 3G alternator, and a Taurus electric fan.

The car currently has a 2.79 gear in the 8 inch rear, but I have a 3.00 or a 3.25 chunk I can swap it out for (the Capri the new motor and trans is coming out of has a 3.08 gear from factory). I usually run between 70 and 80 mph on the interstate every day, just running along with traffic, about 85% of the driving I do is on the interstate. You're right that the pulley is very different on the '80 engine, the car it's coming out of had P/S and A/C. Can I just swap the balancer off the '70? Will the front sump oil pan off my old motor work on the '80 engine?

You're right that the pulley is very different on the '80 engine, the car it's coming out of had P/S and A/C. Can I just swap the balancer off the '70? Will the front sump oil pan off my old motor work on the '80 engine?

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The pan will swap and damper should also swap but maybe you could just change the pulleys instead of the damper. Check if the bolt pattern spacing is same. If you weren’t planing to change the trans for the srod, I would say just swap the head, but think you will be way ahead in time by putting in the 80 complete. I have had some trouble with my early heads wiping the guides too some bronze guides and hard seats on the exhaust would cure that. Drove many of the early 200 engines and also the late 200’s I think you will really like the 80 engine they do seam to pull a little stronger on low end.

i do agree on the pulling a little bit more on the bottom end taking off from a light in my mustang it ould twist twist the chassis. even with brand new shocks and bushings. what v8 does that stock??? hehehehe ive actually been afraid of it doing some damage so in the near future i may install tower braces.