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S-10 V8 Conversion
Page 1 of 2

     The Small Block Conversion in any S-10, being a pickup or Blazer, is not that hard, believe it or not. All you really need is to do a little planning, talk to a lot of people, and BE PATIENT!!!

   Some modifications need to be made to the engine bay before installing the motor.  First, use a 5 pound sledge hammer and beat back the lip around the bellhousing (see photo)   Next, beat the passenger side area where the firewall meets the floorboard.   This gives additional room for the headers.

enginebay.jpg (42775 bytes)passhead.jpg (31151 bytes)

  The most popluar transmission choices are either the TH-350 or TH-700R4.  The 700R4 has overdrive which is nice for highway driving and fuel economy.  The 350 trans is much stronger and can take more of a beating.  (Although I use the 700R4 it works great, not stock though)  It is recommended that you use the 168 tooth flexplate.  You may use the stock crossmember but may have to make some mods to fit the transmission.   S-10's originally with  the 4.3 engine should require no modifications using the 700R4 trans.  The ears of the bottom of the TH-350 bellhousing area need to be trimmed off for clearance.

  If going through emissions is going to be a concern to you, consider the use of the stock exhaust manifold.  The only ones that will pass emissions are those used on the low-performance V8 82-92 Camaro/Firebird.  You will need to use cylinder heads from 1978 and newer for these manifolds to work correctly.  Also, to use these manifolds, you must use a passenger side dipstick, otherwise major interference problems will occur.   You will also need to grind approx. 1/8" off the drivers side manifold flange to clear the steering shaft.

exhaust.jpg (19939 bytes)

  If you are not concerned about emissions, I recommend using headers.  Heddmen hedders makes a nice affordable set of shorty style headers that are specifically for the conversion.  The part number through Summit Racing is HED-69520.  You will have to bang back where the firewall meets the floor pan on the passenger side for clearance for the collector.   Nobody makes a dual exhaust kit for the 82-93 S Trucks so you need to have pipes custom bent.  If your truck is dropped, good luck in getting the pipes to exit out the back.  I dump out right before the rear, plus that makes it louder!!

  Your stock V6 alternator can be used by switching the pulley to one used on a V8 alternator.  The front bracket (GM #14015533) adjuster (GM #14081227) and spacer (GM #6262934) must be used also.  If replacing a 4 cylinder engine, its is easier to buy a new V8 alternator to provide the correct amperage.

   It's best to substitute a V8 power steering pump in place of the V6 pump.  The two have the same capacity, but using the V8 pump will allow you to use the stock GM brackets.   Use brackets from 81-84 full size "C" Series pickup.  You also need to get the proper V8 pulley for belt alignment. 

pump.jpg (39783 bytes)

pump2.jpg (41076 bytes)

If replacing a 4 cylinder motor you must purchase a new starter.  I recommend using one from a 91 Blazer 4.3 engine.  This will work with the 168 tooth flywheel with no clearance problems and is very durable.

You have the option of using an electric or mechanical fuel pump.  If your V8 engine is carbeurated, then you must supply 5-7 pounds of pressure.  If you S-10 originally was fuel injected, it has a high pressure fuel pump inside the gas tank.  YOU CANNOT USE THIS WITH CARBEURATED ENGINES WITHOUT A REGULATOR! It may be easier to disconnect the electric pump by removing the two relays mounted on the firewall.  You do not have to drop the gas tank and remove the pump this way.  Just run gas through the pump and use the same fuel lines and use a mechanical pump.  Another option is to use a fuel pressure regulator (Holley 12-803) to make the pressure 5-7 psi.   Mechanical pumps can be used relatively easily.  The fuel line needs to be extended and brought under the oil pan to the pump.  I use steel braided hose from the pump to the carb.   If your V8 is fuel injected, then you should buy a new high volume electric pump.

fuelpump.jpg (26248 bytes)


Questions about the V8 Conversion? Email me