I would do both heads. Not sure on your car if one side or the other is more difficult to get. On my 84 500, by the time I got the fuel distributor and intake off it was most of the battle. My block is also aluminum and did not require any helicoils. Just lucky maybe. I would second the pindelski site as worth the $30.

Good Luck.

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dloveless

1984 500 SEL [131K]-
1991 GMC Sierra 4X4 XC [162K]- War Pony.
2004 Jeep Liberty Limited [8k]- wife's sled- Belle.