We’ve finally completed our 408ci stroker small-block Mopar build for Project Track Attack. We did a little mixing and matching, but weren’t exactly pioneers in the LA block/Magnum head build. We did discover a few things that were not only important to the build, but not well known in the community. What that means is, every time we rounded a corner, we were met with unanswered questions.
For example, using rocker-arm stud girdles was suggested, but nobody could direct us to valve covers that would clear them. We aren’t the first ones to use these parts, but we had to find a solution on our own. We reached out to other builders, shops, manufacturers, and finally stumbled upon the solution. This article is to help others with our discoveries.
We knew we were already on a different path by starting with anything other than a Hemi or a big-block. Our unorthodox path took several turns along the way to the completed build. It was highly recommended by Mopar enthusiasts to use a 1970-1973 block. They’re getting harder to find, and sometimes the price isn’t worth the risk of finding out the block is cracked. We found a 1973 block from a friend in Dulzura, California. Luckily, they let us have it for a great price.
Breathing is important, so we opted for Edelbrock’s Magnum heads. Their improved flow characteristics and compatibility with the Chevy 1.6-ratio roller rockers that we received from COMP Cams made them ideal. We counted on Scat Crankshafts for our rotating assembly with custom JE Pistons. After a few months at the machine shop, the build was ready to commence. Below, we’ll share some secrets and tips, in case you decide to perform a similar build.
Trick Parts To Enhance The Build
It would be nice to have the money for an R3 race-block, but the best blocks are either too expensive or too difficult to find. A 340 build would have been better, but who can find a buildable 340 block these days? One look at Hughes Engines, and we found a main-stud girdle to help tighten up the bottom end. The girdle can mount in one of two ways: by machining the caps flush with the girdle (preferred) or using spacers.
There are kits available to convert to a four-bolt main, but drilling into the block’s lower webbing is rumored to weaken the block. We opted for the stud girdle instead. The girdles are very affordable, and is a wise addition if you’re heading past the 400 horsepower mark. David Hughes told us, “I’ve had several customers with 700 horsepower naturally aspirated builds, and they’ve been doing just fine.”
We’re not interested in launching on a sticky track with sticky tires, at “I can’t hear you” RPM. In other words, we aren’t concerned with living our Belvedere’s life “ten seconds at a time.” We do plan so see some high numbers, but we’ll leave the “1,000 horsepower” to the braggarts. We’re not just about numbers here – we’re about driveability and usefulness.
We’ve been told that a windage tray is a nice addition. However, we also heard that one used in conjunction with a main stud girdle is a bit of a pain and can be problematic, so we chose to stick with our original plan.
If you only race your car a couple times a year, you should still make sure to build it with that in mind. It’s ill-advised to expect your street cruiser to handle the punishment those trips to the track will dish out. Our initial build was a slightly warmed-over street build. A few times at Willow Springs we noticed the oil-pressure gauge dancing on the lower psi readings during hard cornering.
We opted for a true road-race pan from Milodon to combat that potential rod-tossing hazard. Milodon had the only true road-race pan we could find. What makes this pan different from a standard deep-sump pan or a drag race pan is the baffling. Drag race pans have baffling to combat the sudden rush of oil heading towards the back of the pan at launch. Conversely, road race pans have baffling that keeps the oil in the pickup area during hard cornering.
Another advantage of the Milodon pan are the side kickouts that allow for a full 6 quarts of oil. It does so without increasing the vertical limitations a lowered car will have. It is also a mid-sump design like the original pan (trucks and vans had rear sump) and will clear the factory K-member. That includes 1967-1973 cars with later K-members. With our Control Freak tubular K-member, the Milodon pan will just clear the Flaming River steering rack in the early B-body.
Many of you know, changing your oil can be a mess if you have a Mopar small-block with headers. The filter is directly above the secondary tubes, and the area is tight. A stubborn oil filter can be difficult to remove no matter how careful you try to be. A few drops of oil will collect around the tubes just before the collector, making it near impossible to clean up.
Once you start the engine, a worrisome smell accompanied by smoke will cause your heart to skip a beat. Sure, some people are experts, but a cloud that looms over some of us has a slightly blue tinge to it from all the times we smoked our headers.
There are other oil-filter relocation kits on the market, but we love the billet piece from Hamburger’s Performance Products. The “IN” and “OUT” are clearly marked on both components for an easy routing of the fluid lines. The unique attachment bracket allows you to clock the filter mount in numerous positions as well. This helps direct the fluid lines in various directions. The horizontal fittings – as opposed to vertical – give this filter mount a lower profile. All of this equates to increased mounting possibilities.
The kit comes complete with four straight 3/4-inch -16 ORB-type (O-ring) barbed fittings and two sections of 15-inch braided, reinforced -12 hose to run between the block and your desired location. You’ll enjoy the ease of changing filters once you go remote.
The oil dipstick in LA engines is typically on the passenger’s side of the front timing cover. It’s impossible to run a tube straight into the opening – the tube needs to snake around the front-drive components. Add the billet fuel-pump-cover plate on our Billet Specialties Tru Trac front drive system to the mix and you’ll have a very difficult time installing anyone’s dipstick tube. Milodon had the solution for us. After two failed attempts with an eBay dipstick tube, we succeeded with the Milodon unit in a few seconds.
At the base of the block, the dipstick will need to take a rather sharp turn away from the timing cover. With the flexible braided sleeve of the Milodon unit, we simply used an open-end wrench for leverage and tapped on it to drive the end of the tube into the block.
Our builder suggested that we strengthen up the top end with a rocker arm stud girdle for this build. We searched the Internet and it led us to Jomar Performance – the only rocker-arm stud girdle that we could find for a Mopar small-block (it’s not an SBC, you know). The stud girdle was designed specifically for the Edelbrock Magnum heads we’re using – imagine that.
We made friends with John Ansteth at Jomar Performance. If you decide to give him a call, you might as well sit back with a cup of joe and be prepared for a series of fascinating stories of trial and tribulation about boat engines, horsepower, and the good old days! He came up with the idea after buying a magazine with an article about breaking rocker-arm studs, and felt there had to be a better way. In 1966, a prototype for his own 1965 Corvette with a tired mill proved to be beneficial, increasing his RPM and performance – and he contacted a patent attorney.
John said, “In virtually all engines with a stud-mounted rocker system, the rocker-arm stud is inclined towards the valve stem. When the rocker arm opens the valve, compressing the spring, the stud is deflected away from the spring towards the pushrod.”
That deflection results in a decrease of effective 0.050 lift on valve open duration. Connecting all of the studs together with the girdle eliminates that deflection and stabilizes the valvetrain. John tells us the benefits to the top end equate to a slight power increase. It also ensures that your rocker arms don’t budge, eliminating the need for constant valve-lash adjustments. On top of that, John says, “The stud girdle is virtually maintenance free once correctly installed on an engine.”
We asked if it’s always necessary, and he did say that mild street engines will seldom benefit from a stud girdle. Many high-performance engines will run okay without one, but those with stud-mounted rockers will typically run better with the Jomar stud girdle. They’ve run a lot of dyno tests over the past 53 years, and have seen anywhere between 10 and 30 horsepower gains. He does warn about ‘over-camming’ an engine and using the girdle, suggesting to make sure the cam is right for the rest of the engine.
The rocker arm stud girdles were a great find, but that lead us to clearance issues with the valve covers – anybody’s valve covers. We asked around, trying to find valve covers that could clear the stud girdles. We got the same answer from everyone we asked: “I don’t know – have them made.” That wasn’t giving us much confidence, but the stud girdles were installed, and we weren’t turning back.
We contacted a company that makes valve covers. They wanted us to send them a cylinder head and valve cover in order to build a new “tall” valve cover. That was too costly, so we contacted a local company that already had the Magnum pattern. After about three months of empty promises, we decided to hit the internet again. We eventually found Dan Medice of Medice Manufacturing, in Cochranton, Pennsylvania.
They say timing is everything, and for us, it was perfect timing. Dan was just finishing up his Magnum valve cover spacers, CNC machined from 6061 billet aluminum. Dan has been at this game since 2005. After buying his own machine shop in 2011, he now has 35 engine families for which he builds spacers. He sent us a couple pairs. After matching them up with a pair of Edelbrock’s thick valve cover gaskets per side (Part # EDL-7593), we opted to install the 1/2-inch spacers, which gave us the clearance we needed.
From: TTi Exhaust
Part #: TTi 340BE-C4
When it comes to headers, you can probably find a dozen or so headers for a SBC. For Mopars, there are only a few. One company that makes headers for Mopars only, is TTi Exhaust, in Corona, California. The old Polyhead 318 we were running was quite limited on performance parts, and TTi was the only company that made real headers for the A-block engine. We were able to loan our car to the team for test fitting of the Poly headers, so we were already familiar with the quality. It only made sense to go back to them for headers for the new engine, and that was for a couple of reasons.
TTi focuses on the various aftermarket companies producing parts for Mopars by sticking with a specific marque. You’ll find references to Schumacher engine mounts, Control Freak Suspension, Edelbrock cylinder heads, et. al. The headers are mandrel bent on CNC machines, meaning the tubes aren’t compressed where the pipes bend. They’re made to exact specifications each time. One other area of importance to TTi is consistency: they’re consistent with the location and the clocking of the collector flange on every set of headers they make.
As with our case, swapping engines doesn’t require having a new exhaust system fabricated, because we are already running TTi headers on the old engine. The new TTi headers will bolt directly to our existing exhaust. They design all of their headers to be body-specific, meaning the collector flange is in a fixed location on every set of V8 headers they make. If you’re swapping from a small-block to a big-block, keep your exhaust and just purchase new headers for the new engine – they’ll bolt right up.
You might think $840 is a lot for headers, but a custom set will run you even more to get this quality. They’ll also clear our Silver Sport Transmissions A41 automatic, another common upgrade that Mopar owners have done over the years. The design isn’t just to route the tubes away from other components, the headers are designed to deliver the best possible performance.
Some of these components aren’t exactly new discoveries to the Mopar crowd, but they were very trick components for us. Some were difficult to find, and others were easy to find if you knew where to look. All of them are what helps make our build a little unique and ready for the track – or our next trip to Vegas.
We would be remiss if we didn’t mention another component that’s renowned in the automotive world: ARP bolts. We relied heavily on ARP to put this engine together, and we used ARP nuts and bolts from the valve covers down to the oil pan, including engine mounts.
We used ARP polished stainless steel 12-point nuts and bolts to pretty-up our build. They’re even stronger than the grade-8 bolts that you find at automotive and home-improvement stores. We also liked the fact that many nut and bolt combos use different wrench sizes, like our engine-mount bolts, so we didn’t need a matching pair of box-end wrenches. Bolt sets are available for many common engine families, in both polished or black oxide and with 12- or 6-point bolt heads. The bolts are rated at 180,000 psi, which makes them the only choice for both good looks and strength.
We’ve spent a bit of time creating the next powerplant for Project Track Attack. As they say though, Rome wasn’t built in a day – and neither is an old-school Mopar. Until the next installment, enjoy the gallery below.