The Saleen package used a 5 liter version of the Modmotor. Ford has had several ways to achieve what they call a 5 liter Modmotor. One of the earliest was the FR500C road race Mustang engines. Those cars used a purpose built aluminum block with a 3.700" bore and a 3.543" stroke for an actual displacement of 304.8 cubic inches. In the FWIW bucket 5 litres is 305.12 (actually 305.118) cubic inches. Of all the 5 Litre variants FORD brought to life the race only FR500C came closest to the 5.0 litre mark. The car and engine were untouchable in class while Ford offered the car. This is a pic of what the block looked like;
Notice the very high valley floor between the cylinder banks. This was coupled to the crankcase to mitigate pumping losses associated with the pistons going up and down the cylinder bores. The high floor also meant that there was no room for the OEM intercooler Ford used on the Terminators. Additionally the large 3.700" bore, actually 94mm, only left less than a quarter inch of gasket sealing surface between bores. The actual dimension was 0.24 inches. This was marginally OK for a n/a engine and in general a bad idea for a s/c engine - unless you o-ringed the heads with a figure 8 style o-ring.
This is a pic of a normal 4.6 Aluminum block and you can easily see the difference in the valley floor between this block and the FR500C block.
The Saleen option came with a 5 litre engine. They engineered a 3.750" crank stroke instead of a 3.542" stroke to get to its 5 Litre displacement. The intellectual and emotional problem was that crank only produced 297.3 cubic inches of displacement. Of course the righteous truth sayers of automotive virtue would have no part of a 297 inch motor masquerading around as a 305 inch motor - where are the missing 8 cubic inches?
Somewhere some particularly disturbed individual stretched the 3.750' stroke crank to 3.800' to righteously produce yet another 5 Litre engine that yet again fell short of the 305 inch gold standard. The 3.800" stroke crank only came up to 301.2 cubic inches.
Both the 3.750" and 3.800" crank 5 Litre solutions had a special problem. Using the 5.933 stock length rod would either compress the ring package so tightly it impaired its operation or if you went to a significantly shorter rod to regain ring package space, the piston would hit the counterweights. The compromise solution was a 5.850" rod length for the Saleen project that over the years has become known as the stroker rod. It is available even today in Manley's catalog.
Once we had broken the glass, so to speak, on the use of a non-standard rod length, why stop there? You are already in custom country so lets tweak a bit more. Back before Honda journals became all the rage in NASCAR the über desirable journal diameter was the 2.000" SBC journal. Not only was it the go to journal for crank manufacturers, it was the go to journal for all the rod bearing manufacturers, who made their most advanced bearing technology offerings available only in SBC journal size. Even today there are specialty bearings only available in SBC dimensions (and now Honda also) that can not be obtained for any other journal size.
Surprise, surprise the Saleen rods were manufactured for use and sale in a Ford vehicle using SBC journal dimensions.
So why did I use them in my engine and not talk very much about it? I didn't want to start a lot of emotional flame thrower sessions about the "optimum" rod for our engines. I like the 5.850 rod because it allows me to use a generous ring placement on the piston w/o the wrist pin entering the oil land - for me this is a personal big deal. The other benefit is I gain access to a rich variety of otherwise unavailable (over the counter) custom race bearings. This in aggregate puts yet another smile on my face.
There is no reason anyone else could not use these rods if they wanted to do the pushups to make them work. It is worth while noting that when you cut the rods 0.010" undersize many cranks will relax and kick the mains out of alignment mandating you also cut the mains 0.010" under size. When you get done then you need to renitride the entire crank. The nitriding is about $300 and the journal work is probably around another $300 or so which means you are into the crank for an additional $600+. That's the bad news.
The good news today is that you can usually pick up a crank with a spun bearing for $100 to $150. Add $600 to it for the trip to the beauty shop and you come out in a worst case scenario as a push with a pristine used crank or more likely $250+ cheaper than a new aftermarket crank. Pistons are a wash because you were going new anyhow.
Ed