Dave Birdwell
May 25th, 10, 9:24 PM
I'm looking at getting one of the aluminum block versions of the 5.3 for a street rod, to keep the weight down. Is there much difference between the two versions? I'm thinking they are both DBW...
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SSR71 May 30th, 10, 9:46 PM The only significant difference will be the oil pan. The Trailblazer's LM4 had a pan with a tunnel cast in to run a drive shaft over to the right front wheel. The '03/04 SSR had the same engine. The weight difference is only about 75 pounds though. The advantage of the iron block is that you can bore it out to match the specs of the LS1. V8TEC Jul 31st, 10, 11:54 PM The L33 had slightly higher compression than the LM4 (9.9:1 for the L33 vs 9.5:1 for the LM4). I believe the LM4 had the standard small-valve aluminum heads (1.84" intake valves I believe), where the L33 is the 5.3 HO full-size extended cab truck engine with LS6 heads (2.00" intake valves). Both had electronic throttle control (except in full-size vans). LM4 info: http://archives.media.gm.com/division/2004_prodinfo/powertrain/truck/index.html L33 info: http://archives.media.gm.com/division/2005_prodinfo/powertrain/engines/05_truck_engine_specs.html#l33 Good luck. :beers: | ||