In the April ’11 issue, we introduced our E-Rod swap project, dubbed the EcoNova, and explained our rationale for choosing the lesser appreciated later X-body platform to those who may not immediately understand the appeal. To briefly recap: Our ’76 Nova represents the first year required to pass smog certification in California and the standard cutoff model nationwide regarding most legislation involving classic car emissions regulation. Plus, we contend that these cars are affordable and underappreciated entry-level muscle with great potential as comfortable daily drivers or weekend play toys. Speaking of that, ours is actually due for smog testing again before its next registration, so it’s time to get to engine swappin’!
As we make our first steps toward 430 clean horsepower, we’ve enlisted the fabrication, wiring, and retrofitting expertise of BS Industries. Both of Bodie Stroud’s last two major projects, the Scarliner in the April ’11 issue and the ’69 Mustang in last month’s issue, feature complicated electronics and EFI swaps. This will be a piece of cake comparatively, thanks to GM’s forethought.
Since ’75-79 GM X-body cars share the same front subframe as ’70-80 F-body cars, dropping the E-Rod LS3 into the engine bay is a fairly straightforward process, but there are a few things to know going in, as well as a couple of newly released parts from Holley, that will make the process go much more smoothly and quickly. Because we want to help take the fear out of a swap like this, we’re going to show you exactly what’s necessary to get an LS3 sitting in the engine bay before we dive into the plumbing and electrical requirements.
Some GMPP E-Rod engines are...
Some GMPP E-Rod engines are plucked off the Corvette assembly line and arrive with Corvette center-dump manifolds, but will include the appropriate rear dump ones from ’10-and-later Camaros. This is the one pretty much all muscle car swaps will require.
Holley has made life easy...
Holley has made life easy for second-gen F-bodies, fourth-gen Novas, and any other GM cars that use the clamshell-style mount with these exclusive steel adapter plates. They bolt directly to the block on the forward bosses. Holley offers four variations of the adapter plates that position the engine differently; ours is the “stock” location, which effectively puts the engine as far rearward as possible.
Luckily, the interference...
Luckily, the interference is in a noncritical portion of the bracket with plenty of reinforcement. Bodie Stroud used a plasma cutter to make quick work of the thick steel, but a grinder or torch could do the job as well.
Next, with bolts snugly threaded...
Next, with bolts snugly threaded into new ⅜-16 hex nuts rather than the original flanged-style nuts, we positioned the lower plate of the clamshell on the subframe so the nuts dropped into the holes. Stroud then TIG’d the nuts onto the plate.
Interestingly, simply cutting...
Interestingly, simply cutting along the outline of an embossed triangular shape on the mount creates the perfect clearance. It’s almost like GM saw this swap coming …
The best we can figure, GM...
The best we can figure, GM never intended for the rubber isolators to be replaced, since getting to the nuts is damn near impossible—unless you feel like removing the springs and lower control arms. With Stroud’s help, we managed to finagle ’em out, but devised to make reinstallation easier. First, we drilled out the rivets to separate the two sides of the clamshell mount and drilled out the SBC mounting holes on the subframe to ⅝ inch.
We backed the bolts out while...
We backed the bolts out while the mount was still hot and then chased the threads. The subframe holes were hogged out to 11/16 inch to account for the welds and then Stroud positioned the plate per factory SBC location and welded the plate flush to the subframe. We followed up with Eastwood’s Extreme Chassis Black paint for corrosion protection.
The top bracket of the clamshell...
The top bracket of the clamshell bolts to the plate with the supplied Allen head capscrews from Holley with no issue on the driver side, but on the passenger side this boss will prevent the bracket from meeting the adapter plate.
Speaking of isolators, future...
Speaking of isolators, future replacement is probably a moot point if you replace the original rubber ones with poly pieces from Energy Suspension. These have a much longer service life and fight torque roll much more efficiently.
With the lower half of the...
With the lower half of the clamshell fully assembled, we’re now ready for trial fitment of the E-Rod LS3.
Here is Holley’s new swap...
Here is Holley’s new swap pan (left) next to the factory Corvette LS3 pan. The integral GM baffling is good, but Holley’s design is more effective at keeping the oil near the pickup under hard acceleration or lateral loads. Speaking of pickup, note the different routing of the tube, which will require a little alteration to the LS3’s windage tray. Also note that the “Oil Change Required” sensor will not be retained.
Back on the engine, it should...
Back on the engine, it should look like this with the Holley tube installed. Make sure to rotate the engine by hand to ensure there aren’t any clearance issues with the crank; we had no issues with ours.
So close, yet so far away!...
So close, yet so far away! Positioned as far rearward as possible, the front edge of the Corvette pan was sitting on the crossmember. This is a common issue with LS swaps in most classic muscle cars. Cutting a relief is doable, but we prefer not to slice the structural suspension parts when there are better options.
With the Holley pan bolted...
With the Holley pan bolted in place, the E-Rod drops right into place, and there’s so much clearance we could practically fit our head between the sump and the crossmember.
This is that better option...
This is that better option we where referring to: the just-released LS swap pan from Holley. This low-profile pan will work for most vintage chassis, thanks to a compact design and a sump moved as far rearward as possible.
In this photo, the larger...
In this photo, the larger indentation near the blue Sharpie is the location of the original pickup tube. The indention we’ve outlined needs to be cut out to clear the mount for the new tube.
Included with the Holley pan...
Included with the Holley pan is a GM oil bypass with gasket and a spin-on filter adapter.
With just those simple changes,...
With just those simple changes, the E-Rod LS3 drops right into the ’76 Nova engine bay like original equipment. We’re loving how far back the Holley mounts place the engine as well. The number one cylinder is inline with the ball joints, which combined with the lightweight aluminum block will definitely be beneficial to handling dynamics and weight bias.