MoparIt has long been assumed that, of the Big Three, Chrysler-sourced muscle equipment is the most difficult to obtain, but a quick pass through the latest Mopar Performance catalog should dispel that myth. These days the factory is fully behind the performance heritage of the Pentastar and proves it by offering not only parts, but complete crate engines for just about every performance-oriented V-8 engine family ever to roll out of Highland Park-small-block, Wedge, Hemi; they're all in there. The only potential shortcoming hard-core purists may find is the absence of the original small-block crates, known as the Commando series. These were the LA-type engines that were replaced by the Magnum small-block in the early '90s. The Magnum generation is very similar to the LA, differing mainly in the cylinder heads, though modifications are required to swap heads between types. The simplest route for someone looking to re-power a vintage Mopar is probably to stick with the LA engine. Unfortunately, the end of production vehicle use for the LA soon meant the end of the crate program.
However, there are still two LA-type crate short-blocks offered by Mopar Performance and they're reasonably priced. The first is good for roughly 9:1 compression and the other for 10:1, depending on the cylinder heads used. In addition to being factory-assembled, the LA short-blocks also include performance-oriented items like KB-Silv-O-Lite pistons and an MP 508/292 camshaft. We know from experience that they can take abuse, as Hot Rod has been running one outfitted with aluminum heads that has made numerous dyno pulls and dragstrip passes, many of them hit with nitrous. After several years, it's still kicking, turning in consistent times and holding good oil pressure. Our Mopar combination based on this short-block is somewhat similar to the 360 built for the Battle of the Titans shootout (Aug. '03), which performed admirably on the dyno.
The last of the old-school LA-style Mopar small-blocks direct from Mopar Performance are actually remanufactured, so the block is over-bored (0.020 inch) and the crank and rods are reconditioned. However, the quality of the work and the parts used appears to be of excellent quality. We considered making the necessary changes to bolt on Magnum heads, but then found that Aerohead offers '70s-era 360 castings fitted with 2.02/1.60-inch valves for only $499; for an extra $100, you can get the more desirable 915/587 castings. These worked so well on our Titans Chrysler engine we decided to use them for this combo. One of the bonuses of the MP 360 LA short is the inclusion of a 508 cam and a double-roller timing set, though you'll still have to provide the lifters. All in all, a stout package for prices that almost rival small-block Chevy thrift.
Start With:Mopar Performance 360 LA Short-BlockBlock: Reconditioned (0.020 over) Chrysler iron 360 LA-typeCrank: Reconditioned Chrysler cast-iron stock stroke (3.58 inches)Pistons: KB Silv-O-Lite hypereutectic flat-top 1.58-inch (PN 4876907) or 1.63-inch (PN 4876908) compression heightRods: Reconditioned Chrysler forged steel, stock-length (6.123 inches)Camshaft: Mopar Performance hydraulic flat-tappet cam (292 advertised duration, 0.508-inch lift)Lifters: Not includedTiming set: Double-rollerTiming cover: Stock aluminum