Engine swap

[Buck]

Hello all. I need some thoughts on the engine in my Mercury. As I had posted earlier this year, after 7 years being parked in the garage, I had gotten my Mercury back on the road this summer. I drove it for a couple months and found a lot of bugs, some due to sitting, some due to age and some due to some mistakes made along the way.

Here are the basics. Its a 1978 Marquis with the 351M engine and FMX tranny. Underpowered with a weak transmission. I have updated to dual exhaust, Mallory Unilite distributor, an Edelbrock Performer intake and a Holley emissions legal 4bbl. Everythng else is stock.

The bad-most of the emission parts are either not working or missing. I cap off the vacuum whenever I find a leak, but I'm thinking I wouldn't be upset to see it all go. There is a vacuum leak in the intake and the carb needs a rebuild. I didn't realize how rich it was running until I overheated one of the convertors and plugged it. Slight valve cover leaks, but not burning any oil or antifreeze. I suspect that having sat for so many years, the valve train is a mess and if I'm going to get that far into it, I might as well pull it and have the bottom end looked at as well.

So with all that, I am trying to decide the best route to go. I am not married to the idea of keeping this engine and tranny. What I would like to achieve is:

1. Improvement over the 150 hp the car had new.
2. Reasonable mileage (It used to get 21 on the highway and mid teens in town.
3. Reliability. I will give up power to be able to drive across country if I wanted to.
4. As low a budget as realistically possible.
5. While not too concerned about emissions, I would like to keep the cats and tune reasonably to be somewhat eco-conscious, unless the results would be minor.
6. I'm not looking to make this car fast. I would like to be able to get out into traffic without worry, but behave more like a cruiser.

So with all that in mind, do I keep the engine and tranny and rebuild? Are the parts I put on it worth keeping or are there better choices? Drop in a Windsor or a 460? Go nuts and drop a diesel in it? Regardless of engine, what would be a good trans choice? How much work to maybe upgrade to an overdrive trans?

Thanks in advance.

[kobrak]

And spend a bit on a good tune up. Other than maybe some performance updates like intake and exhaust. ditch all the smog crap and it wil not only run better, but more than likely cleaner.

[Buck]

I did a pretty intensive tune up this summer, but with all the other issues, the results were marginal.

[Buck]

I've decided that I will be staying with the m engine that's in the car now. The trans will bolt up and the intake, etc that I already have will save me some money and conversion issues that I don't know if I could handle.

Here are my questions. The price I got for a carb rebuild was around $250 which isn't much less than what I paid for it. Does this sound right? For the money, I'd rather go with something different since the need for emissions is no longer required.

I think due to the amount of work that would need to be done to rebuild the engine, and since I am staying primarily stock, I am going to go with a long block replacement, possibly upping to the 400 since everything I already have will work. Of the national suppliers, does anyone have good, bad or indifferent experience with any of them? Does anyone in the Minneapolis area know of a good local company? Am I wrong in thinking it would be more expensive to rebuild my current engine than buy a reman?

[Buck]

Following up to the above. I'll be pulling the car out of the garage hopefully early next week. Due to ability, money, time and tools, I am limiting myself to the following.

1. The intake has a vacuum leak, so I'll pull that, clean it up and replace. Both valve covers as well
2. the remaining not functioning emissions valves will be coming off.
3. the quote I got to rebuild the carb starts at $250, so I'll probably just buy a new one for the money.
4. All of the "Tune up" parts were replaced last summer, so nothing new there.
5. The big one, and what I need some recommendations of other Minnesotans, is the exhaust. I parked it last year because it started giving me fits on the way home from work. I limped it to a parking lot and found both converters glowing red. I knew it was running rich, but pushed it anyway. It wouldn't run over an idle, so I had it towed home and parked it. I am going to assume that both have plugged themselves solid. That said, I need to get the converters replaced or eliminated, neither of which I can do. Any suggestions for shops in the area?

I have the front bumper and front body components, but still need a ds fender before the body work can be done. I will drive a little longer with the body damage, I just want it to run.