Genuine MRP Product
-For high rpm use
-Strengthens bottom end ladder caps
-Machined from 4340 Billet steel
-Nitrided
-Fits only with ARP Mainstuds
-Compares similarly to Tomei reinforced main caps.

MRP has done it again. With many years dealing solely in 4AGE/7AGE performance, MRP has been able to identify any weaknesses in Toyota's 4A/7A design when pushing their builds to and past the 600hp mark. With sustained high revs or tremendous amounts of boost, the main caps begin to stretch as a result of the massive amounts of torque exerted by the crankshaft.

The crankshaft won't likely break, but any distortion of the main caps will allow centralized stress points on the engine main bearings if allowed to on for any measurable amount of time. By machining a backbone for the main caps out of a higher grade steel than the OEM main cap, MRP's reinforcement caps can help to retain the integrity of the lower block.

We recommend using this MRP product when consistently revving your 4AG past 8000rpm, or if you are making more than 250hp with the help of forced induction/nitrous injection.

***These main caps will only work with ARP main studs*** This usually works out, as engine builders often upgrade to ARP main studs when building a high performance 4AG.

**This item stocked in California**
Included in this kit are 5 MRP main caps, and a printed instruction guide. ARP main studs are also available through Battle Garage Racing Service elsewhere on this site.