jims427

Does anyone have knowledge of someone putting a crate 502/502 in a mid year. I am planning on pulling my 427/425 to refresh it and thought I might have some fun before putting the 427 back in. As I've stated I plan to put the 427 back, so I don't want to do anything while installing the 502 that I can't reasonably undo. I know about the clutch ball bracket that can be purchased and I know that I will have to mount an electric fuel pump. My 66 has side pipes, so I may run into some problems here as I try to find some sort of header-to-pipe connection. Your thoughts are welcomed.

achapman

I have seen several in midyears, fit with no problems other than what you have described. There are several here in the forum that are running 542 CI... I guess 502's are too tame.... :lol: :lol: :lol:

67HEAVEN

The main issues with a 502 are:
1. lack of boss for clutch linkage swivel (in oil filter area)
2. lack of mechanical fuel pump boss (requiring electric fuel pump)

TheOman

Clutch pivot is a no brainer. Lokar, Lakewood or somebody makes a bracket that bolts on with the same bolts that hold the bell housing to the block. Scoggin Dickey carries it along with lots of other people.

The fuel pump boss is one of those dim bulb GM things I just don't understand. They must have gotten a "Brain Freeze" from drinking frozen margarettas tooooo fast just before they finalized that design "improvement"!

Viet Nam Vett

I have seen a 66 with a 502 Crate Motor at a few shows that I attend. It looks lke it was made to fit. He had tube headers on it and just had enough clearence to get buy. The owner stated it was an awsome ride!!

TheOman

I wonder why more folks don't realize that the external dimensions of all the BBC's are the same. With the exception of dumb moves by GM like the clutch pivot and the fuel pump boss everything is more or less the same.

Even the tall deck big blocks from the trucks are externally the same as the passenger car blocks in terms of mounting points for accessories and motor mounts. Obviously the intake manifolds and pushrods are different but that is rather minor. I sometimes wonder why more tall deck engines did not find their way into passenger cars. All ya need is a little bit of custom fabrication of exhaust pipes from the exhaust manifolds to the mufflers. The tall deck engines are only about 3/8 inch higher than the passenger car engines. Somebody even made spacers to allow the use of standard passenger car intakes on tall deck engines.

Viet Nam Vett

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I wonder why more folks don't realize that the external dimensions of all the BBC's are the same. With the exception of dumb moves by GM like the clutch pivot and the fuel pump boss everything is more or less the same
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Here-Here--- Well said

MELVIN

Folks, Yes the 502 will fit, no prob, BUT:

If you use the gm intake and carb you could have clearence probs with the hood. You could use your stock intake IF its an oval port intake. Your stock distributor, water pump, valve covers, starter all will fit the 502 if you desire

The clutch issue is handled this way:http://www.sdpc2000.com/cart.asp?action=prod_detail&catid=1006&p id=8875

richscorvettes

Jim,

It's a fairly straightforward conversion following what everyone else has said especially, in your case, since it's already a big block car. If it wasn't you would also have to consider the radiator size, use of big block radiator hoses and factor in the impact on handling given the increase in weight. In your case the 502/502, with the aluminum heads, should weigh less than what you have now. The clutch plate is readily available as is the fuel pump. You will have to do some playing with the air cleaner (either using a drop base or making something) as well as the exhaust hookup. I used Sanderson headers and fabricated the connection to the side exhaust. Sanderson made the headers to match the aluminum head exhaust port shape and clear everything. If you have power brakes you will also have to watch the clearance between the valve cover and brake booster.

Another consideration could be the life of the universals, transmission and rear end if you plan to really use all that torque. As long as you don't use real sticky tires those components should last okay.

We have some pictures of one installation on our web site shown below. If you decide to go that route and have any questions I'd be glad to try to help.

Rich Lagasse

StrayDog

Why wouldnt your 427 exhaust manifolds work on the 502 , so the side exhaust would match up ? OK :confused: , as the big/block dimensions are supposedly equal, for example I have Endlebrock Alum heads on my 427 & they also fit a 502 , I am using stock 66 big/block exhaust manifolds on my 427 with Endlebrock heads & factory side exhaust with no problems......... :seeya


[Modified by StrayDog, 9:09 PM 7/17/2002] :flag


[Modified by StrayDog, 9:10 PM 7/17/2002]

427Hotrod

You might do some calling around, but I hear through the grapevine that they are going to release a 502 with a mechanical pump boss on it finally. The boat guys have been complaining. Maybe you can find a newer production one instead of an older one out of stock. Not sure if this is definitely going to happen, but it possible.

You could also get one of the Bill Mitchell Merlin's. He's selling 509's and 540's for similar $$ that have better parts and more power. Plus they have the clutch ball boss and fuel pump stuff already.

That 427 will be doing garage duty for a long time once you drop the hammer on one of these dudes! Mine is!

Jim


[Modified by 427Hotrod, 12:03 AM 7/18/2002]

Colevette

Stay Dog your correct you can run the 427 manifolds, we run them on ours just for the break in period before installing the headers. We did have to notch the back side of the manifolds to clear the head bolts.
Cole :yesnod:

MassVette

Even the HO 454 that GM is selling as a 'drop-in' replacement for 'muscle-car' and Corvette motors lacks the clutch pivot boss! I know- I bought one!
bunch of dumb @#$$$***!!

MELVIN

Fellas: The one thing that will not fit off a 427 onto a 502 are the stock exh manifolds. Im living proof. My 68 L-36 exh manifolds would not fit as the head bolts on the 502 will hit the top of the exh manifold runners. Maybe lower profile heads on the bolts would work, Im not sure. My headman after markets would not fit either because of the same issue, so I modded to fit

The clutch boss isnt an issue. The earlier post I posted will show one, and you can make one from the pic, like I did. The lack of a mech fuel pump boss sure does suck though