Well – there’s some good news and some “not-so-good” news. Your block was produced from 1969 to 1979 and used in cars, trucks and even in a few Corvettes. It came in 2 and 4 bolt with advertised horsepower ratings from 185 to 370. Not bad. The heads - another story.

The 882's have hardened seats and that tends to make them prone to cracks. They were one of the first factory hardened seats and it took GM a few years to get this right. Some would tell you that 882's are the "best" of the worst heads.

There are two good “versions” of this head:

L48 (1970 – 1980, cars, trucks and some Corvettes) w/1.94 intake/1.50 exhaust, 76 CC Chambers - flow is not-so-good, i.e., intake +/-137cfm, exhaust is a measly 95cfm. These are the early series used in the low output (believe it or not, 1973 Corvette used this and was rated at 190HP!). These are the most crack prone!

L82 heads (1973 – 1977 Corvettes and some Impalas - 210 – 250 horse,) had 2.02/1.60 valves, guide plates, 76cc chambers, 151cc intake runners and flow increased to 206 cfm on the intake and 145 cfm on the exhaust. With some “gasket matching” porting you can squeeze another 10cfm on both intake and exhaust. With “serious” work, the L82’s can get into the 226/158 cfm range but you need a real head pro machinist and be prepared to part with a paycheck - $750 plus – but why would you rework a tired old smog head when you could get a set of Vortecs or go aftermarket.

There were actually three series of these castings. The third is a “red-headed step child” that uses 1.72 intake and 1.50 exhaust - that was used on 2 barrel truck/passenger car applications. They look deceptively like the L48, but trust me – they different (use a .3750 [3/8”]” stem as opposed to the .3414”).

See if you can find a set of used 96-00 Vortec 350 truck heads they flow 229/162 cfm stock and don’t seem to be as prone to the cracks. Some on ebay for $500 w/free shipping. Another set of 12558060, brand new for $585.

Hope this helps,
Glenn