Chevy LT1 Head Questions - Performance Q&A

Kevin McClelland Jun 1, 2009 0 Comment(s)

Of the two camshafts that would work great in your towing application, we lean toward the XR264HR, which specs out at 212/218 degrees duration at 0.050 inch tappet lift, 0.487/0.495 inch max lift, ground on 110 centers. The largest camshaft we'd use is the XR270HR, with specs of 218/224 at 0.050 inch, 0.495/0.502 inch max lift, also on 110 centers. These camshafts will produce right at 500 lb-ft of torque, with the shorter producing around 425 hp and the larger closer to 450.

Round out your package with a large dual-plane intake, either the Dart Iron Eagle/Pro 1 dual-plane or the Edelbrock RPM. And finally, don't be temped to put primary tube headers larger than 15/8 inches on the engine. The 400 will love the small primaries, but they must be long-tube headers to support this engine.

This should give you a very nice, totally bulletproof small-block for your tow rig. Good luck, and let us know how it turns out!

Sources:
compcams.com
dartheads.com

Need A Lift?
Q: As a longtime subscriber to CHP, I hope you can help with my problem. The '82 El Camino that I bought new now has 70,000 miles. Because of my health problems (lungs), the VA gave me a handicap lift and scooter, mounted on the El Camino. Everything was fine for about three months and then the OE factory air shocks started to leak down to 20 pounds in about four days. I had a friend replace them with Monroe air shocks. They leaked down in one day! They were replaced three times with the same results. We checked every possible way to find leaks and couldn't find them. My friend seemed to think they were leaking through the rubber around the shocks in a way that we couldn't detect. I had him install Monroe Sensa-Trac (load adjusting) shocks. I measured the height at the rear wheelwell. It was 27 inches, and after we installed the lift (100 pounds) the height was 25 inches. Loading the scooter (150 pounds) the height went to 21.5 inches. Do you know of heavier rear springs that could be installed maybe from a 1/2-ton pickup? I don't care if the El Camino rides 2 or 3 inches high in the rear when I'm not carrying my scooter, and the lift stays on at all times. Hope you have an answer. Thanks.
Bert
Via email

A: Boy, we're sorry you've been fighting with the air shock system on your Elco. The factory air shocks are a really good system. It's unfortunate that they got tired and gave up. Yes, there are springs out there that will work. Let's take a look.

Moog Chassis Part, a division of Federal Mogul, offers what it calls its Cargo Coils just for your needs. They're variable-rate springs that change resistance as they compress and become stiffer as the load increases. This is accomplished by winding the springs with a progressively tighter wind toward the top. The looser wind at the bottom gives you a normal ride with no load in the bed, but as soon as the loose wind compresses, the stiffer, tighter windings hold up the weight.

You have two choices: The springs that are spec'd out for your Elco are PN CC627, or you could go with the stiffer wagon springs under PN CC507. We've used Cargo Coils before with great successes, and the standard El Cam springs should take care of your 250-pound payload. Both part numbers are available from Summit Racing.

This should take care of all your problems hauling your scooter. Hope this will get you around a little easier. Good luck and good health.

Sources:
federal-mogul.com
summitracing.com

Technical questions for Kevin McClelland can be sent to him at chevyhi@sourceinterlink.com.

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