Ok, so anyone with any mechanical aptitude that's owned a mid-80's caddy knows that the HT4100 is a money pit. Mine is no exception, though it hasn't (completely) failed me yet.

And I stress YET.

But rather than rebuild a substandard engine such as the one in my 1985 Eldorado, what other options do I have?

I'm planning on making this a project car, and retiring it as my daly driver, at least until the spring.

One option would be to find a used 4100, strip it down to the block andgo from there (aluminum heads being the key change). But apparently mine is the only one in a 200 mile radius, and S&H would make up the diffence in cost if I were to buy a reman.

What I'd like to do is build an engine from the block up, but starting from a more powerful, more fuel efficient template than the stock for my model year. But I don't know what kind of engine would be compatible with the rest of my drivetrain.

Is that possible? Is there something like a big block V6 that would fit and function properly in my vehicle? Would the mounting bolt patterns effect which engine I can get or are there conversion kits available?What problems am I likely to run into with a project like this? How much could I end up spending and where can I save a few bucks without endangering a successful outcome?

I'm still a novice when it comes to this stuff, so any guidance, suggestion, tips, ridicule or otherwise is greatly appreciated.

Thanks!

What year is the car, seems to me is it is not a downsized car you have the Olds 307, 350 or even 403 or Cadillac 368 or 425 as choices. If downsized you are stuck with 4.5 or 4.9 Cadillac.