Converting your L series to EFI is certainly possible. A number of people here have done it. But the advice given above is good advice. One thing I can agree on is that you really want to plan this one out, because it won’t be easy.
Here is a thread that I started which parallels my build, but deals with the issues I had while doing the EFI conversion.
viewtopic.php?f=3&t=4476
What you will need is access ot machining and fabrication facilities. And you have to be able ot think outside the box. The problem with the older engines – no matter what make – is that the ports, casting bosses and mounting areas you need for the correct placement of the EFI bits won’t be there.
I ended up using the water drain port in the block, and machined a special adapter which would still be the plug, but then would also accept the GM style knock sensor I incorporated.
Coolant ports were an interesting issue, I wanted to keep the stock gauge, run an autometer gauge but also needed the water temp gauge for the EFI – it was interesting finding all the ports for this.
I needed to fabricate a mount for the crank sensor, because the L obviously didn’t have such an animal.
And of course I also needed to make a front pulley which would incorporate the magnets needed for the Hall Effect crank trigger.
Since I went distributorless and wanted full control over my timing curve electronically, I needed to build a distributor support bearing for the oil pump/distributor shaft.
The list goes on, but the information is out there. I come from only one perspective – many out there would do it differently. Also the technology today has change from 10 years ago when I built this set up, so you still have to think outside the box and work within the capabilities that you have.
Concerning output – 180 HP at the wheels is absolutely obtainable with an L20B. I’ve seen the dyno runs personally with local cars. Our last dyno day saw 3 L powered 510’s at or over 180 HP at the rear wheels.
HOWEVER, these are highly tweaked cars, and not happy doing the daily grind. Big cams, temperature sensitive, funny gas…
If you want a nice driving, simple to start and operate car then 140-150 HP is about as good as it gets. Trust me on this one. I’ve done the big cam thing, it’s not all that glamorous when you just want to cruise some times.
Note: I am a diehard L series guy. But I will tell you that starting with an already EFI motor will put you miles ahead in every aspect.
Concerning your chassis – there are many idea in that department. But here is a link to one of my builds on my chassis and how I made the L work in it.
viewtopic.php?f=27&t=530
Lots to look at and take in.
Start by posting photos of what you have, what your capabilities are, what and where you have to work with, what your time frame is and most importantly what you end goals are. From there, this group on the realm can point you in any direction you want to go. It’s unlikely you will come up with something that has not already been tried – success or failure. Trust us on this one, we’ve seen lots of failures. However the best thing about failures is that you learn and it proves you are trying.
Start a thread, lay it out and keep us posted.
Byron