The blocks are not the same. The 3400 V6 engine is based on a 60 degree design and the 3800 V6 90 degree. The Eaton M90 Gen3 blower is technically too big for the 3400 engine. The problem is the heads are different to include the lower intake manifold so trying to bolt up the M90 blower from the Grand Prix GTP is not really bolt on. There are Grand Am and I believe Alero owners that transplanted the complete L67 SII 3800 engine.