73 nova v8 swap from an L6

i have a 73 nova with the factory L6 that i took out. i bought a 400cid motor and trans from a 74 impala. can i use the motor mounts from my L6? and is there anything else i have to look for?

You may need to beef up the front suspension, I hope it was not the 2 speed transmission some novas had in that era.

but i can still use the L6 mounts? yeah it did have the 2 speed powerglide but now i have the trans that came with my motor from the impala

You are correct to wonder if the “mounts” can be used. You should concern youself with perhaps the pedestals the mounts attach to must be changed. Rear transmission mount is almost certain to need changed as is crossmember.

Probably not as bad as putting a V-8 in a previous 6cyl early Mustang.


You’ll probably have to upgrade to a larger radiator to handle the larger engine.


No, you’ll need different mounts for the new motor. I would bolt the mounts to the new motor, lower it into the bay and center it on the crossmember. Then mark the crossmember for the mount locations and hoist the engine back out. Now take the mounts off the engine, locate them on the crossmember and drill the new holes.

The trans mount can be done next with the engine/trans propped up. If I’m not mistaken, the frame rails are not boxed and so the crossmember can easily be removed and re-located.

The shift linkage will have to be addressed.

Your driveshaft will need to be reworked to get the proper length (likely shortened, balanced and new joints).

Front springs will need to be beefed up.

As mentioned, a larger radiator will likely be required and you’ll need to pay attention to get the shroud properly positioned around the new fan location. Best to find a junkyard shroud from a car that might have originally had a similar combo- perhaps a Camaro of that vintage.

That’s all I can think of off the top of my head…

Have you Googled “Nova engine swap”? There’s are several good sites, and project histories out there.

I echo Twin here . . . and recount the old addage “measure twice, cut once”. In this case, measure three times before you cut into (drill) the frame rails to install the new mounts. Rocketman

I would also suggest “beefing up” the rear springs.

Novas were notorious for “crab walking” after a few years, likely the result of torque on those monoplate rear springs. If the torque of the original L6 was more than the rear springs could withstand without deforming, just imagine what the V-8’s torque will do to those springs.

Personally, I would replace those monoplates with real leaf springs. A good, experienced spring shop should be able to come up with real leaf springs that are of the correct length and are appropriate for the torque of that engine.

The entire rear end will have to be replaced, as will the brakes. You can’t just stuff in a big V8 engine without creating a death-trap…

Here’s book for $17 that might answer some of your questions:

thank you everyone who replied with the useful info. i just want you to know that the motor actually did fit in with the original mounts from the L6 aparently the L6 and the 350 V8 used the same engine mounts, but it was a tight fit and fought with me the entire time. the trans cross memeber was fine aswell but the drive shaft will have to be shortened down to 50 1/2". as far as the front suspension it held up pretty well not much lower from the L6 so i think ill leave it alone for now. the shift linkage doesnt quite work but i think i may just go with a floor shifter to save me the trouble of fabricating the linkage. but thanks again everyone for the help!

You were able to do all of this in just 3 days? Sounds a little fishy,like it was already done when you posed the question.

yeah i was able to with the help of a buddy. i had already taken the 6 banger out when i asked the question. you dont have to believe me i could care less. im just saying thanks for taking the time to post info