Page 240 of GM Performance Parts 2006 Catalog by GM Parts Direct

Bowtie V-6 Bare Block (rear) A Bowtie V-6 Bare Block (front) A NOTE: 238 V-6 90 ENGINE BLOCKS 10205294 Cast Iron Bare Block Cast iron bare block as used in production 4.3L 90 V-6 engines with 4.00" cylinder bores and two-bolt main bearing caps. Uses one-piece rear main seal and is machined for either roller or flat tappets. Has two oil galleries and an open lifter valley. It cannot be converted to V-8 style lubrication. Heavy-duty and pre-1986 production crankshafts with two-piece rear seals can be installed using seal adapter P/N 10051118. A. 10185051 Bowtie V-6 Bare Block Fully CNC-machined block with siamesed 3.980" cylinder bores that can be bored to 4.155". Deck height is 9.025". Features 8620 steel main caps, priority main oiling, 2.00" O.D. cam bearings and wet sump oiling. 25534333 Sportsman V-6 Bare Block This is a fully CNC-machined Bowtie block similar in size, dimensions and features to block P/N 10185051 (see above), except it has nodular main bearing caps and Grade 8 bolts. CHEVROLET V6-90 ENGINE BLOCK QUICK REFERENCE CHART Part Number 10205294 10185051 25534333 10134371 10134351 Block Material Iron Cast Iron Cast Iron A356-T6 Aluminum A356-T6 Aluminum Cylinder Wall Type Non-Siamesed Siamesed Siamesed Siamesed Siamesed Cylinder Deck Height 9.025 9.025 9.025 9.025 9.025 Cylinder Bore Range 4.000" 4.000-4.155" 4.000-4.155" 4.125" 4.125" No. Bearing Cap Bolts 2 4 4 4 4 Cap Bolt Orientation Straight Splayed Splayed Splayed (20 deg.) Splayed (20 deg.) Bearing Cap Type Cast Iron 8620 Steel Cast Nodular 8620 Steel 8620 Steel Crankshaft Journal Dia. 350 size 350 size 350 size 350 size 400 size Oil Sump Type Wet Wet Wet Dry Dry Crankshaft Seal Type 2 piece 2 piece 2 piece 2 piece 2 piece Design Max Stroke 3.75" 4.00" 4.00 4.00 4.00 Weight (lbs bare) N/A 163 163 78 78 Intended Usage Amateur Comp. Professional Comp. Professional Comp. Professional Comp. Professional Comp. Non-Standard Parts Required Has fuel pump boss No mechanical fuel No mechanical fuel pump boss pump boss CHEVY V-6 60 AND 90

[close]