Ian, welcome aboard. Just finishing up a two year restoration on a Federal model here. The Plus 2 would make a fantastic weekend car, and is a lot of fun to restore. It is probably the most under appreciated early Lotus. Agree with Gerry to consider the fibreglass condition as the most important issue when selecting one, but also consider your own preferences and be selective in your choice as well. Having just completed a five speed conversion in a new Spyder chassis, I would certainly go for a Plus 2S/5 if available; we really never got them in Canada so this wasn't an option for me.
What ends up the least desirable is a "bitsa" car with all kinds of mix and match parts sourced from several different models so that it is hard to describe what is being offered. However, many have been upgraded over time with various aftermarket mods, big valve heads, new wiring, etc. to improve reliability, which strikes me as a good thing, although concours folks would have a different view.
The hood bulge you asked about was put on to accommodate the Stromberg carbs, which are higher in profile than the Weber's or Delorto's. At this point cars could have had the head/carb set-up changed, but that was the original purpose.
Here is a link that has good descriptions of the various model changes over time. We had lost this site from the 'net, but was recently revived by a member of the list, which is great
http://lotuselan-plus2.be/trevorsparrow ... npages.htmIn addition, we had a few threads in the last couple of years describing various small Plus 2 model differences, more focused on what parts properly belong on the various cars. The site can be searched in the upper right. Try searching on "differences" within the "Plus 2" section and you will see a few threads to check out.
To search the site with Google add the following command into the end of a Google search:
site:lotuselan.net
Edit to the other questions/posts:
Keep in mind I have never driven the Lotus five speed, so my preference for a overdrive gear of some kind remains, but I definitely do not have the experience Terry does with the Lotus box. Note they are relatively rare to find used at this point.
The 3.54 diff was a Lotus provided option when the cars were new, but apparently relatively rare in the Plus 2. Even with the MT75 five speed I have installed I would still like to convert to a 3.54 from my 3.77. Note the gearing change appears to be on the order of 6%, and would make first gear taller, which may make the car a bit harder to drive in creeping traffic, particularly with the Rotoflexes installed. Solid drive shafts are absolutely the way to go and solve drivability problems, really transforms the car. Taller first is not an issue with most of the after-market five speed conversions as they tend to have unusually low first gears based on their original sedan use. Taller gearing is perhaps more of an issue in NA; I have to travel 120 km at freeway speeds of ~75 mph just to get to my first corner in the Rocky Mountains
, so tall gearing to keep up with the Honda's is a real help
Changing the diff is very much a PITA job in the stock Lotus chassis due to clearance issues; much easier on a Spyder chassis as they added space in this area. Can be done by a home mechanic, but just a frustrating job even with the body off.
Ian, if you are test driving various cars and wondering what ratio is installed, there is an easy to use spreadsheet on a Westfield site that allows you to plug in various data and get the RPM's at various road speeds, so you can determine the diff ratio. David on this site has posted an excellent spreadsheet that provides all of these numbers as well.
Question for the list; are the ring and pinion for the 3.54 ratio readily available new so I can get the conversion done locally by a specialist? It is very difficult to get a complete used 3.54 on this side of the pond and I would like to convert prior to getting my speedo modified. Most of the one's that come up on eBay UK will not ship to NA due to the weight, and they appear to be in good demand in the UK.
HTH