How to Make a 327 Using a 350 Block

Chevy’s 327 engine first appeared in 1962, and five years later, it became the 350 engine. The 327 and the 350 are from the same engine family, meaning that most of their parts are interchangeable. Both engines share the same bore, but the 350’s added displacement is due to a longer stroke. Converting a 350 to a 327 requires replacing the 350’s crankshaft with a 327 crankshaft. However, due to the shorter stroke of the 327, the compression ratio would be drastically changed. Therefore, both the crankshaft and the pistons must be changed.

Things You'll Need

• Wrench
• Harmonic balancer puller
• Snap ring pliers
• 327 pistons
• Piston ring compressor
• Connecting rod bearings
• Engine assembly lubrication
• Crankshaft bearing
• 327 crankshaft
• Timing chain cover gasket
• Oil pan gasket

Instructions

1. Remove the oil pan and the oil pump. The oil pan is secured to the bottom of the engine with 18 bolts. Remove the bolts with a wrench and lift the pan off of the engine to expose the oil pump.

2. Remove the two mounting bolts and lift the pump out of the engine. A metal pole, called the oil pump’s drive shaft, will slide out of the pump as the pump is removed. Pull the shaft out of the engine after removing the pump.

3. Remove harmonic balancer, followed by the timing chain cover and timing chain. Remove the single bolt from the center of the harmonic balancer with a wrench, then attach a harmonic balancer puller to the face of the balancer and use the puller to pull the balancer off of the tip of the crankshaft.

4. Remove the 10 bolts which secure the timing chain cover to the front of the engine with a wrench, then pull the cover off of the engine to expose the timing chain.

5. Remove the bolts and pull the larger sprocket off of the camshaft, which will cause the chain to go slack. Pull the small sprocket off of the tip of the crankshaft.

6. Disconnect the eight connecting rods from the crankshaft with a wrench. Each connecting rod attaches to the crankshaft with two bolts. With the bolts removed, each connecting rod’s cap can be lifted off of the crankshaft.

7. Grasp the connecting rods and use them to pull the pistons out of the engine block.

8. Remove the two bolts from each of the crankshaft’s five caps with a wrench, then lift the caps off of the crankshaft. Grasp each end of the crankshaft and lift it out of the engine.

9. Disconnect the pistons from the connecting rods. On either side of each piston is a snap ring. Remove both snap rings with snap ring pliers, then push the piston pin out of the tip of the connecting rod, which will disconnect the piston from the connecting rod.

10. Install the 327 pistons onto the connecting rods and into the engine block. Position each piston onto its connecting rod, then slide the piston pin through the side of the piston and into the tip of the connecting rod.

11. Install the snap rings onto each side of the piston with snap ring pliers to secure the piston to the connecting rod. Three rings surround the base of each piston. These rings must be compressed into the side of the piston with a ring compressor tool. With the rings compressed, gently push the pistons into the engine block.

12. Pull the old connecting rod bearings off of the connecting rods, then liberally coat new bearings with engine assembly lubrication. Snap one half of the new bearing onto the bottom of the connecting rod. Snap the other half into the rod’s cap.

13. Pull the old crankshaft bearings out of the engine and off of each of the crankshaft’s five main caps. Liberally apply engine assembly lubrication to both halves of new crankshaft bearings, then press one half of each bearing onto the engine.

14. Press the remaining half of each crankshaft bearing onto the crankshaft’s caps. Lower the 327 crankshaft into the engine, then tighten each crankshaft cap bolt to 80 foot-pounds of torque with a torque wrench.

15. Grasp the bottom of each connecting rod and pull the bottom toward the crankshaft. Slide the connecting rod’s cap over the two studs on the bottom of each connecting rod, then tighten each connecting rod’s two nuts onto the connecting rod cap to 35 foot-pound of torque with a torque wrench.

16. Install the timing chain and timing chain cover. Wrap the timing chain around each of the chain’s two sprockets then slide the small sprocket onto the tip of the crankshaft and press the larger sprocket against the camshaft. Tighten each the larger sprocket’s three retaining bolts with a wrench. Install the timing chain cover over the timing chain with a new gasket, then tighten each of the cover’s 10 bolts with a wrench.

17. Install the harmonic balancer, followed by the oil pump and the oil pan. Position the harmonic balancer onto the tip of the crankshaft, then tighten the balancer’s single bolt to 60 foot-pounds of torque with a torque wrench. Lower the oil pump’s drive shaft into the engine, then lower the oil pump onto the engine. Tighten the oil pump’s two bolts, and bolt the oil pan to the bottom of the engine with a new oil pan gasket.

References

• "Motor's Auto Repair Manual;" Ralph Ritchen; 1968
• “Chevy Small-Block V-8 Interchange Manual;” David Lewis and Pierre Lafontaine; 2009