Help on engine selection

[MRose]

Hi all. This is my first time posting. I have a 1970 Challenger convertible I have been working on for two years. It had extensive rust damage which I have repaired using mostly AMD replacement panels. The car is now at a body shop ready to be painted it's original Plum Crazy color. the car originally came with the 340 option and it was advertised as numbers matching. Unfortunately, although the date code on the engine is 1970, I found out later from the vin stamp that the engine was originally out of a 1971 vehicle. Too late to do anything about it now but it left me with a question. Since the engine is not original, I'm trying to decide on rebuilding the 1970 date coded 340 engine I have or go with a 440 big block. I want to go with the option that would bring more resale value in the future. If a go with a 440, it would include the six-pack option. I need to make a decision soon so any advise will be much appreciated. Thanks.

 

[Mopars & Missiles]

#1 - Welcome to FEBO

#2 - Pictures of your car are MANDATORY!

#3 - "the option that would bring more resale value in the future" - What makes you think anyone here has a crystal ball that can predict that any better than you can? What you will get is a bunch of "opinions" (everybody has one) that vary greatly. For instance, my opinion on future resale value is to "keep the car as ORIGINAL as possible" to fender tag and/or build sheet if you want the highest resale value.

What you have described sounds like a very cool and somewhat rare Challenger. I'm sure I'm not alone in wanting to see some photos of your car and resto-mod work.

Good luck!

 

[MRose]

Here are a few pictures of the car when I bought it and where it is at now before it went to the body shop. I'll try to post some more later. The car is currently stripped down to the bare shell so it's a blank canvas. I probably still have over a year's worth of work to finish the car. I plan on keeping this car and enjoying it for years to come. I always liked the 440 engine which is why I am considering it but the 340 is a great engine too. Just looking for opinions I guess. Thanks.

 

[Adam]

What is the number on the engine? I would love to find my missing 71 340.

 

[moparlee]

Welcome to the site. Will be a very nice vert when you get it done. My opinion.......also keep it original to the vin tag.

 

[RUNCHARGER]

If it was mine I would keep the 340 as well.

Sheldon

 

[Mopars & Missiles]

Here are a few pictures of the car when I bought it and where it is at now before it went to the body shop. I'll try to post some more later. The car is currently stripped down to the bare shell so it's a blank canvas. I probably still have over a year's worth of work to finish the car. I plan on keeping this car and enjoying it for years to come. I always liked the 440 engine which is why I am considering it but the 340 is a great engine too. Just looking for opinions I guess. Thanks.

Looks like its coming along nicely. Yes, you have a ways to go yet. Those body shops are notorious for taking 5 times as long as they say they will. The 440 is a great engine, but a bit heavier than the 340 (which is a great engine too). What kind of driving are you planning on doing? 340 is great for cornering, but the big 440 can't be beat (well, maybe a Hemi) for straight line acceleration! Again, if it was originally a 340 car, I would sure be building it that way now. Or at least keeping and storing the 340 for later just in case. Thanks for the pics!

 

[DetMatt1]

A66 convertible should stay a 340 in my opinion. Welcome to the site from the Motor City!

 

[MRose]

Yep. I think staying with the 340 is the right decision. Just needed to hear it from a few others. Thanks all for the opinions and suggestions.

 

[DetMatt1]

Good choice, so does it have a fender tag?

 

[340challconvert]

I am really glad you are keeping the car a 340.
Your sheetmetal work is looking exceptional.
I also own an A66 340 convertible that I am finally making into a driver. (owned since 1980)
In the long run, the closer you stay to the fender tag, the better.
You have a pretty rare car there.
Production number for Challenger convertibles from GG's book:
JH27H0B - 340
~ 178 - auto
~ 20 - 3-spd
~ 66 - 4-spd

Good luck with your build.

 

[aussiemark]

340 is the best smallblock 4.040""standard bore 4.100 with a .060"oversize (try getting a 4.100" bore from a 350 Chev or 351 Ford) Short stroke for low piston speed at high rpm and a big bore for good power Chrysler engineers were geniuses 340 and 426 Hemi were their finest creations.

 

[MRose]

It has a fender tag. It's originally plum crazy with a white interior and convertible top. Forgot to mention it's an automatic. It's going back to plum crazy but I'm not sure about the interior or top. I prefer black but will probably stick with the original colors. Thanks for the comments. It was a lot of work to get the body repaired. The hardest part was trimming the hard top quarter panels to work on a convertible. Turned out pretty good. Here are a few more photos.

 

[DetMatt1]

Nice work! What's the build date?

 

[MRose]

The build date was late 1969 (October I believe). I didn't catch that until after I purchased the car. It would be hard to have a 1970 date code on an engine block when the car was built in 1969. Oh well, lessons learned for me. At least the engine appears to be in good shape with the correct carburetor, heads, exhaust manifolds, etc. The car was a beater needing a lot of work so my focus was on the body rather than the engine.

 

[DetMatt1]

Your car likely had decals for the engine call-outs on the hood rather than emblems since it was an early car and I am the only source for them. I found an nos pair of them and had them reproduced and my charge for them barely covers cost so let me know if you're interested.

 

[moparleo]

Welcome aboard. 340 gives the best balance of power with good handling. They are nose heavy to begin with, so what ever you can do to lighten up the front weight bias is a plus.

 

[jimynick]

Welcome to to the site and congrats on getting that deep into the body work! I also like the "double cross-peen hammer" lying on the floor in pic 1080. LOL Going to be a great car when you get done, for sure!