Ad Radar
Car Craft
Click here to find out more!

Engine Swap - Easy Big Block Swap

Photography by John Kiewicz

As corny as the old adage is, in most instances it's true: There's no replacement for displacement. And these days, with the availability of stout mail-order crate engines, the cost of buying a brutish big-block is now within the budget of many gearheads.

Case in point: GM Performance Parts' burly 502/502 big-block (PN 12371171) that can be had for about $6,000. In the Sept. '97 "Crate Engine Shootout!" story we tested the 502/502 and were giddy to see 513 hp and 555.5 lb-ft of torque. However, even though a crate engine's price may be lower than what you'd spend building a similarly performing mill, we wondered what hassle and expense would be required to shoehorn such a fat-block into a traditional musclecar.

We'd always heard that a big-block Chevy was an easy swap into a small-block car--but is it true? With the 502 and an A-body on hand, we decided to find out for ourselves and share with you the details and the costs. As usual, CC's much-abused Cheap Street Chevelle was the guinea pig, but much of the info will apply to most '68-'72 GM A-bodies or GM fullsize barges.

After jerking the small-block and test-fitting the 502, the first thing we learned was that the 502/502 comes with a six-quart truck-style oil pan that interferes with the engine bay in our '70 Chevelle. We replaced it with a special Milodon oil pan that merges the correct old-car-shape to fit the chassis with the new-car-type pan rails that fit the new Gen 5/Gen 6 big-blocks and their one-piece rear-main seals and revised gaskets. The Milodon oil pan's unique design has a large seven-quart oil capacity for reliable oiling during racing yet is a low-profile design to avoid ground-scraping woes. Often, you can reuse the 502's stock one-piece rubber oil pan gasket, but if not, companies such as Fel-Pro offer a gasket under PN OS34407R.

SOURCES
Edelbrock
Dept. 5.0
2700 California St.
Torrance
CA  90503
310-781-2222
www.edelbrock.com
Original Parts Group  (800) 243-
Milodon Inc.
20716 Plummer St.
Chatsworth
CA  91311
818-407-1211
GM Performance Parts
www.gmperformanceparts.com
Hedman Hedders
16410 Manning Way
Cerritos
CA  90701
310-921-0404
www.hedman.com
  • «
  • |
  • 1
  • |
  • 2
  • |
  • View Full Article
Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
0 comments
Car Craft