Northwest Nova

→ Nova Small Block V8 Engine Conversion Reference

A comprehensive (but not exhaustive) reference to the parts needed when converting from an L4 / L6 engine to a Chevy small block V8 in the 1962 - 67 Chevy IIs.  Most do not realize how many parts were actually unique to the V8 cars, many within those unique to the Chevy II.  This is likely a factor in the complete hack jobs performed over the years on these conversions, either adapting incorrect parts from other models or poorly fabricating substitutes (or both).  Virtually everything is now available reproduction and plenty of good used parts are still around, so there is no excuse not to do it correctly. 

--QUICK HISTORY--

The V8 engine was first introduced in 1964 with the 283. The 327 appeared in 1965. Both were available through 1967. No big blocks until 1968.  There were the obvious differences found with the performance 283 and 327 engines, air conditioned optioned cars and as well as A.I.R. (smog) equipped motors, but these details are of concern only to purists and stock restorations.  GM made revisions to parts and application during this period, but for conversion purposes, it is the same process regardless of model year 1962 - 67.

--ENGINE BLOCK--

The 1st and 2nd gen models used an engine block with features unique to the Chevy II.  It is not required to have a correct block for the conversion, but understanding the differences can be helpful.  They are:

• Recessed oil filter boss — so the filter would not hit the steering center link OR to clear the clutch linkage. The "why" varies between who you ask. Regardless, if it presents an issue it can be overcome with a smaller oil filter or filter relocation kit.
• Relocated clutch z-bar block-side pivot ball boss — moved forward on the block to deal with the tight confines of a Chevy II. An inexpensive relocation bracket is readily available for mechanical clutch applications.

--KEY ITEMS--

• The following assumes use of a 1979 or earlier two-piece rear main seal small block engine.  Later small blocks will obviously work, but often have specialized conversion requirements.
• Alternator and accessory mounting should be planned out prior to conversion.  Many mounting brackets are unique to the Chevy II and becoming scarce (expensive).  Some reproductions exist. Many convert to a low-mount alternator (bracket kit available).
• Stock or close to stock subframe and suspension setups unless otherwise noted.
• The factory shop and assembly manuals are a great reference for this conversion. They are strongly recommended.
• A 5-lug suspension conversion should be made as well for 1962 - 63 models. The 4-lug setup was not meant for a V8. Disk brakes are strongly advised.

 

 Most items normally in stock, reproduction or good used GM; NOS parts on occasion. 

Part	Description	Need	Comments
OIL PAN	Front sump with driver's side dipstick boss on side of pan. 1st & 2nd generation Chevy II specific.	Required	Original production run pans differ from later GM service replacement in the size (width) of the front and rear mounting lips where the rubber seal goes.  Higher quality gasket kits will come with both versions of the seal.  There is variation of the internal baffle as well, but that is of no concern in the conversion.  The reproduction pan is of acceptable quality.
Oil Pump	Specific to the Chevy II front sump oil pan.	Required	USA made OEM quality replacements are still available, but there are indications production may be coming to an end.
Oil Pump Pick-up Tube	Specific to the Chevy II front sump oil pan & pump. Much longer than a normal SBC piece.	Required	OEM GM replacements are not hard to find and we often have them in stock.
Oil Pump Drive Rod	Specific to the Chevy II front sump oil pan & pump. Shorter than a normal SBC piece.	Required	USA made OEM quality replacements are still available.
Oil Pump P/U Tube-to-Block Bolt	The standard pump p/u has a flange that is bolted to a boss drilled into a main cap web. This is specific to Chevy II blocks. Some non-Nova blocks have space for this hole to be drilled, many do not (4-bolt main blocks). Hi-performance Chevy II motors w/ a windage tray (i.e. L79) have special main cap bolts with studs at the top. One of these studs retains the hi-po pick-up tube shaft via a unique flange, rather than a bolt into the main cap webbing.	Recommended	For motors using the standard p/u (most engines) a custom solution has to be implemented for securing the p/u shaft. For motors running the L79 style pump p/u, the special main cap studs are available new.
Oil Dip Stick	Specific to the Chevy II front sump oil pan. Mounts on driver's side front of the pan.	Required	Original parts had a green rubber grommet or plug at the `eye` hook for assembly line identification. The reproduction uses a black plug and is of fair quality. Original GM recomended when you can find one.
Oil Dip Stick Tube	Specific to the Chevy II front sump oil pan. Mounts on driver's side front of the pan and has a flange that secures to an exhaust manifold bolt.	Required	Reproduction is of fair quality. Original GM recomended when you can find one.
Engine Frame Mounts	Specific to the Chevy II. No variation between performance and non-performance applications.	Required	Reproductions range in quality. Good used original GM are not hard to find.
Motor Mounts (Rubber)	Not specific to the Chevy II, but specific to period SBCs.	Required	The generic parts store motor mounts often do not fit properly. Make sure to get application specific mounts.
Accelerator (Throttle) Arm	Specific to the Chevy II, though other makes look similar. The L6 one is smaller and shaped differently.  At some point during second gen production GM started using the V8 one for all motors. I have only seen this on 1967 models.	Required	Reproductions are of good quality. Good used original GM are not terribly hard to find.
Engine Feed Wire Harness	V8 specific and also varies if the car was a Super Sport (gauges) or not.	Recommended	Probably the #1 item people half-ass in these conversions, often introducing electrical problems. Reproductions are of good quality and can be ordered for HEI & internally regulated alternator setups.
Exhaust Manifolds	GM used `ram's horn` style exhaust manifolds unique to the Chevy II. Multiple features make them different... (exhaust manifold reference page coming).	Required	Reproductions were available for a time, but not sure they are still produced. Original GM are starting to get scarce, especially in good shape.  Many use shorty headers - Sanderson makes a popular set. Certain period truck ones sort of fit.
Lower Alternator `Pivot` Bracket	Specific to the Chevy II exhaust manifold, there were three different ones - standard, w/ A.I.R. &. 62 amp alternator. The Chevelle one is not the same (often claimed to be).	Required if running stock manifolds	A `replacement` unit is available from the aftermarket. Not a correct reproduction. Original GM pieces are starting to get scarce.
Radiator	Specific to V8 cars. There is a 1st gen radiator and a 2nd gen. A heavy duty cooling option was available but not terribly common.	Required	Another area people cut-corners. Copious aftermarket radiators are available from stock reproductions to high-end aluminum.  We recommend and sell U.S. Radiator brand.
Radiator Fan Shroud	These get kind of messy with Chevy IIs and will eventually have their own reference page. Basically there was a metal radiator spacer used in some years and a plastic fan shroud in others.	Recommended	The 2nd gen plastic fan shroud is available reproduction and can be fitted to the earlier cars. Or you can run an electric fan setup.
Fuel Lines	The V8 line routes to the outside of the front subframe and enters the engine compartment under the battery tray.  The standard V8 line was 5/16", hi-performance applications used a 3/8" line.  Dual exhaust cars the line was routed away from the passenger side exhaust.  The pump–to–carb line also varied dependent on carburetor.	Recommended	The #2 item that people butcher in these conversions. Reproductions are available in both diameters, in standard or stainless steel and relatively inexpensive.  Some repops are USA made. We like Inline Tube. It is an item worth replacing on a 50+ year old vehicle.
Brake Lines	GM used a different front–to–rear main body brake line on the dual exhaust cars.  It was formed to move the line away from the passenger side exhaust.	Recommended	Yet another item that people mutilate in these conversions. USA made reproductions are available pre-bent in either standard or stainless steel.  We normally use Inline Tube. It is an item worth replacing on a 50+ year old vehicle.

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DISCLAIMER This information is provided as a courtesy to the Chevy II enthusiast.  It is your responsibility to verify the safety and efficacy of this information and your related repairs.  We are not in any way responsible for the success and / or safety of your vehicle repair.  Nor are we liable for any bodily harm or property damage, to you or others, caused by faulty repairs.  It should go without saying, but if you do not know what you are doing leave the engine, transmission & suspension work to experienced mechanics.