I didn't ask the original question, but you gave a lot of good advice.Hi there,
Unfortunatley Im in Sweden, so I guess the phone aint such a good idea =)
Anyway, I wrote this down years ago when I did this swap myself. I know there may be some info missing, so feel free to add....
Hope this helps at least a bit:
NOVA ENGINE SWAP
Are you going in thoughts of pulling the old L6 engine out of your Nova/Chevy II and replace it with a small-block Chevy? This seems to be a very popular swap but there are some matters that need to be considered before you take action! I have done the swap myself so I’m well aware of what obstacles you will meet during the installation process. Reading this may help you to avoid some usual mistakes and get better prepared for the job. I know that there are small differences in chassis and parts. No car from this period is identical with another. Trust me! But I'll base my article on experienced facts and not theoretical calculations so I think the information will guide you in one way or another.
First & foremost: Get yourself prepared for some minor modifications. The engine will fit the compartment without problems but it will be tight, real tight! If you are using under chassi-headers they will almost get in contact with the inner fenders and the starter. Some of them will even make it very difficult to change the oil filter without pulling out the tranny and the flywheel/flex plate. There are more things to consider, but let’s start with an inventory of the parts needed for a lucky engine swap.
Oil pan device
First you’ll need a small-block Chevy engine, if you haven’t already figured that out. Take your time and do a rebuild if you are in doubt that the engine is in perfect shape. It will cost you some bucks, but when it’s done you won’t regret it. Then you’ll need the “infamous” Chevy II oil pan together with the special oil pump, pickup and oil pump-slot. This oil pan has the sump at the front instead of traditional Chevy pans, which have the sump at the back. The alternative is to buy an aftermarket oil pan or welding your own setup. Be sure to mount the long pickup to a main cap-bolt and weld it to the pump with care. (Be careful so you not weaken the spring in the oilpump by the heat). Make sure to do this coz Its no fun if the pick up come lose and end up rattling in the pan.
V8 engine mounts & throttle linkage
You will also need a pair of Chevy II V8 mounts (the ones that is bolted to the chassi) because they are not similar to the one that is used along with the L6 engine. You’ll also need the mounts that are bolted to the block. Then you will need a throttle linkage adopted for the Chevy II with V8. You can build one yourself, but it’s not worth the effort because we are not talking “big bucks” here. You can save yourself some time and buy one of these throttle linkages at Year One or Chevy II Only for 40 dollars or less.
I have a word of advice when it comes to the distributor. Don’t pick a HEI distributor if you want to have a smooth installation without trouble. The cap on the HEI is too big and it will in most of the cases not clear the firewall (note, there are exceptions but they are rare). In other words, if you must use one of these distributors you will either have to modify the firewall or moving the whole engine forward. And I just don’t see why you should do that when there are lots of other good distributors on the market.
When you have equipped your engine with the unique Chevy II oil pan and the rest of the parts needed its time to look at the choice of transmission. I will suggest you to use an automatic tranny because of the clearance problem on Chevy II. I know that many have used, and still are using manual transmission on this type of cars, but I have no experience about using a manual tranny in a Nova, so I will skip that in my article. Now, when I am assuming that you will use an automatic tranny, let’s go on!
I think the TH 350 transmission is the best bet for your Nova, if you not choose to play in a higher division and mount a 700R4/200R4 tranny. I prefer TH 350 simply because it’s light, reliable and cheap. First you’ll have to modify the crossmember. It’s really no big deal, just cut off about ¼ inch on the lip that is going toward the transmission oil pan. You will need the extra clearance to clear the pan. Use great patience when it comes to installing the dipstick tube into the TH 350. There is not much space here and maybe you’ll have to modify the tube a bit to get it where you want it. Expect at least an hour of frustration for this “under normal conditions” easy task. Lokar is selling flexible braided hose tubes, I guess those would help. Mount the floor-stick, speedometer-cable, vacuum hose and the cooling lines together with a good oil-cooler preferably placed in front of the engine cooler. Hook up the kick down wire and adjust it right. Check your drive shaft (TH 350 is using the small yoke) and replace/modify it if it won’t fit, then you are in business.
Of course you will need a bigger/better radiator for the V8 Nova, there are lots of aftermarket radiators to choose from out there. I have also used a radiator from a Volvo 240 diesel with success. Remember this radiator was used with a mild 305CUI V8 engine setup and might not be sufficient with a maximum output hot rod V8. To get even better cooling you can buy/fabricate a shroud for the radiator. I did this and noticed a big difference in engine cooling! At last, dont forget to use a good cooler for the transmission as well.
Here is a list of parts required for the engine swap:
Small-Block Chevy engine & TH 350 automatic transmission
Chevy II V8 Front sump oil pan (Or aftermarket Chevy II pan)
Chevy II V8 Oil pump
Chevy II V8 Pickup tube
Chevy II V8 Drive rod
Chevy II V8 Dipstick tube
Chevy II V8 Dipstick
Chevy II V8 Motor mounts
Chevy II V8 headers (available as either fenderwall or under-chassi headers)
Chevy II V8 Throttle linkage
Here is list of a few things that will improve your Chevy II & make your life a lot easier:
Oil filter relocation adapter (If you are looking for effortless filter changes) needed with some under-chassi headers.
A good transmission cooler