Despite 350 is a reliable engine ,I think, a Jaguar should carry a Jaguar engine in it . I have no any idea whether it will a reliable car hence . However at least you have to see no leaks nor other quirk problems related to the engine .350 is a bullet proof one
Other side of the pictureputting a "foreign" part in another car is not what I wanna have namely if it is for Jag .

 

The Chevy engine is bullet proof, as long as you do what you gotta do. Let the engine warm up before running it, oil change every 3000 miles, and after that run it like you stole it. As for electrical problems, what older jaguar do you want, and what's "older" for you? 1996 or 1956?

 

The engine swap can go either way. Be sure that whomever you have perform the swap will be around to work on it. We dread them coming here because we don't know where wiring goes, etc. It opens up a much large can of worms than you see on the surface. The inline six engines are very reliable, they like to leak a lot of oil though. The electrical is what shoots them in the foot. The v12 engine can be reliable if you keep it cool. Over heat it once and you're sunk!

 

I think from late XJ40's electrical system has begu more reliable . ('93 and up ) [&:]. I can't say something for the mileage but at least it should be as good as Chevy

 

Don't expect more than 15mpg that's for sure.

 

Wise choice my friend...wise choice. Although I don't know about a GM? Read up heavily on their forums as well.

 

I almost dropped a 350 in my 86 soveriegn -- then I opted to have the original engine rebuilt. Cost a bit more, but I'm damn glad I did it. I have no disrespect for the Chevy 350 (got one in my 86 K-10 Scottsdale), but it's no jaguar engine. I thought I found a website once (sorry no link) that had some used AJ16's for only $600 if you're still considering a jag engine -- good luck either way.

 

Who is the "Lovely Creature" in this pic?

 

I have converted 2 Jags to Chevie V8. The first was a series 1 XJ6, 1972 as I recall, with 110,000 miles converted to 400 small block with a turbo hydromatic. It was a very successful conversion. The thing got 18 MPG, 0 to 60 was much improved as was handeling. However, the engine was not as smooth as the old 6 and there was a curious harmonic introduced. Not objectionable, just different.

I was a member of the Rocky Mt. Jag Club at the time and I can tell you that I told no one as I valued my life. I sold that car off when I got tired of having nothing to do to it. Big mistake.

The second conversion was a 1986 XJS V12 with high miles. I put in a 455 big block with an R700 transmission. Not a good match overall. I got good gas milage, around 18/19 on the highway and good accelaration. However it ate 2 transmissions, plowed like a bitch in the turns in spite of being lighter in the front and that curious harmonic was present as well. I did get a $1000 for the old V12 engine. I sold that car and was glad to be rid of it. Stay with the lightest engine/trans combo you can find.

Both cars were documented to a fare the well with wiring diagrams and build logs. Because of that I never had any trouble with service at GM or Jag establishments and I had no trouble selling them. In fact I had a list of guys who wanted the cars when I was done having a great time with them.

In sum I would not buy a conversion Jag unless you know the builder was a true hot rod craftsman. There are a lot of details, I kid you not, that must be done right, like spedo calibration, instrumention, penion angles,air conditioning, etc. The proof is in the build documention and wiring diagrams. O yes. If see any evidence of sloppy work run away. If you are concerned about what you can see think of all that is involved that you don't see.