Marine L-88 Engine w/ Cast Iron Heads

**SuperNovaSS** · #1 08-19-2011, 08:13 PM

I picked up an engine yesterday and thought I would share. It is a complete L-88 engine that was built by GM with cast iron heads. The cast head L88 is a subject I have always been interested in. I have seen a few pop up over the years and mos message boards seem to dismiss the engines as being home built or L71/L72 engines with a 3933198 intake added.

This engine was removed from a 1969 speedboat and was the original engine to the boat. It was running 2 days ago. The suffix code is 7BL. I have seen this suffix before and always wondered what it was. The engine has the correct 3933198 intake, 840 heads, heavy duty AC fuel pump, 7/16 dimple rods, and the 7115 steel crank.

**SuperNovaSS** · #2 08-19-2011, 08:32 PM

Here is the engine as it was pulled. The carb is a 3246 service dated Holley. I have seen 3246 carbs on most marine 427s. The pulleys are GM units but are not deep groove.

**SuperNovaSS** · #3 08-19-2011, 08:37 PM

The block is a 3963512 casting with a casting date of B 5 9.

The heads are both 3919840 with casting dates of A209 and C139.

**SuperNovaSS** · #4 08-19-2011, 08:40 PM

The front pad is stamped TO3177BL. The 7BL suffix must mean closed chamber L-88 with cast iron heads.

The 3933198 intake is dated 9.18.68. I believe the 198 intakes were only made in certain runs. I don't think I have ever seen a casting date from October 68-Feb 69 unless the 198 was hand stamped.

**SuperNovaSS** · #5 08-19-2011, 08:41 PM

Factory high lift rockers are still intact.

L88 pushrods still there

**SuperNovaSS** · #6 08-19-2011, 08:42 PM

Cool original fuel pump

**SuperNovaSS** · #7 08-19-2011, 08:44 PM

Pulling the pan was exciting. No denying this is a L-88

**SuperNovaSS** · #8 08-19-2011, 08:45 PM

I decided not to pull the heads since the engine runs great and I can see it is standard bore due to the TRW pistons having GM and the part number on the undersides.

**smallblockhero** · #9 08-19-2011, 10:07 PM

neat find. im really surprisd at the carb. most OE marine carbs have 180 degree vents. having worked at a boat dealer ive never seen one like that factory.

we had at least 4 early 70's BB chevys and fords and the carbs all looked like this

**olredalert** · #10 08-20-2011, 12:25 AM

----Since the carb is service dated I would guess that the owner or mechanic bought an automotive carb when the boat carb went bad. It was probably cost effective at the time, but not too safe......Bill S

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