Got questions?

We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we help a reader overhaul his Rat motor for street/strip performance.

G.T. • Keaau, HI
Q: I have 1973 454 big block Chevy. It has 8.5:1 compression, stock oval port cylinder heads, a Crane PowerMax camshaft, an Edelbrock Performer intake, and a Holley 750 cfm carburetor. The engine needs an overhaul but I would like to retain the stock cylinder heads and intake. What would I need to increase the compression ratio? Also, I enjoy the sound of an aggressive cam—what do you recommend? I want it to be a stout street engine but yet have some fun on the track!

A: For starters, rejuvenate your engine with a Sealed Power premium engine rebuild kit (FEM-CSMHP767). It includes everything you need for an extensive overhaul without breaking your budget, plus you can retain your stock cylinder heads and intake. Once you’ve installed the kit, your compression should increase to around 9.8:1. Keep in mind that these kits are custom ordered by your bore diameter and bearing sizes—talk to a sales expert to make sure you’re getting the proper kit for your application.

As for your camshaft, we recommend a COMP Cams® Xtreme Energy cam and lifter kit (CCA-K11-250-3). It includes a hydraulic flat tappet cam that builds big power from 2,300-6,500 rpm and has 240-degree intake/246-degree exhaust duration @ .050-inch lift. Also included are a set of lifters, a timing chain and gears, valve springs, seals, and locks, retainers, and assembly lube. The aggressive lope of the Xtreme Energy cam will be music to your ears!

Author: David Fuller

David Fuller is OnAllCylinders' managing editor. During his 20-year career in the auto industry, he has covered a variety of races, shows, and industry events and has authored articles for multiple magazines. He has also partnered with mainstream and trade publications on a wide range of editorial projects. In 2012, he helped establish OnAllCylinders, where he enjoys covering all facets of hot rodding and racing.