Big Block to 502 Swap

Has anyone put a 502/502 in their C3? I've got a 454 I'm thinking about swapping. What are the biggest issues to over-come. What Pulleys to use, Z-bar mount, Fuel Pump, Intake Manifold to fit under Stock Hood, Cooling? Thanks, Randy

Hello Randy,

The swap should be fairly straight forward.

You will need an in-line fuel pump as there is not a place to put the mechanical pump.

You will need to replace the water pump with a "short" water pump.(If the engine you buy has a pump already on it.) There may be some minor clearance problems with the timing cover bolt heads. Alittle grinding should help.

Have the radiator rodded out or replaced with a new one. I don't believe that you need to go to any great lengths to keep the engine cool if the cooling system is in good shape.

The accessories and pulleys should bolt exactly in place.

As far as the hood clearance, it depends on your year. 68-72 should not have any problems. Their hoods are high enough to clear most intakes. The Edelbrock Performer is about the right height but whatever you choose make sure to compare it to the original for height. It shouldn't be any more than 1/4" taller. 73-74 BB intakes are actually very short. You can use the original intake on the 502 I think, but HP will suffer since the intake runners actually run uphill to the intake ports.

Good luck!

Alex

|UPDATED|4/29/2004 6:46:54 AM (AZT)|/UPDATED|

Randy;

Check with the manifold mfgrs, Edlebrock says none of their dual plane manifolds will fit under the stock BB hood, the only manifold they have that will is thier Torkerr II. I'm looking at putting Edelbrocks' EFI system on my 72 BB, and figure I would need to go to a L-88 hood for clearance.

NJ BB Ken

That's what I've heard, as well. Thanks, Boomer. Good luck with your BB project.

Alex.....Thanks for your response. What is the reason I'd need to go to a Short H20 pump? Also, I was told by EdelBrock that no current Aluminum intake would fit under my stock 1969 BB Hood. The TorkerII (I've Heard) would be my only option.

if you do get the l-88 hood...

the edelbrock air-gap fits nicely with a demon sitting on it.

Hello,

The short water pump is used to get the needed clearance from fan to radiator. The BB you have currently has the short pump.

The BB intakes for the 69 were not very high, but they had adaquate performance. I am assuming you have the 390hp engine. You may be able to clean up the ports and still be near the 500hp mark. Also the 68-69 Tripower will fit under the hood. You will need to match up the type port (oval or square) to the heads on the 502. I think they are oval on the 502. So the 390hp and 400hp (tripower) will be a direct fit. The 435hp tripower is a square port and should not go on the oval port head.

Alex

Alex,
I appreciate your response. I didn't remember if the pump was long or short on the existing motor...And you assume correctly....I have a 390 hp engine currently. Thanks, again!