S-10 V8 Conversion
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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!!!
THE ENGINE BAY
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.
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
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
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
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.
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.
Questions about the V8 Conversion?