Just wondering if any of the more experienced wrench turners here have any reservations about the Shelby GT500 using an iron block with aluminum heads and other aluminum engine components. I ask because aluminum and iron have different expansion and contraction rates, and it has presented problems for other cars in the past, an example being leaking head gaskets.

Expert opinions...?

 

The '03/'04 Cobras had iron blocks/aluminum heads. I don't recall there being an issue with them. In fact, there have been plenty of engines with that combination over the years and I don't think it's been a problem. But again, I'm no expert so perhaps someone with more knowledge can chime in?

 

Hello.

 

Not a problem. It is very common these days. My 2000 F150 5.4L Has Iron block/aliminum heads and so does my wife's 2000 Avalon....

You just need the correct gasket material that can expand and contract and maintain an acceptable tension.

I would venture a guess ( I said guess ) that MOST cars on the road today have this configuration....

 

 

FE block, AL heads are a very common combo, even on some higher performance models, and with proper engineering and development. ought not to cause any performance or reliability issues.

 

someone wants iron heads now LOL

 

My 427 Tunnelport High-Rise for my '67 Shelby has aluminum heads and I've never had a problem. I don't think there's ever been a "compatibility issue" or something of the like with an iron block and aluminum heads.

 

I had an 85 Capri RS with a 302 iron block and an aluminum intake manifold. At about a 1000 miles the intake manifold gasket sprung a leak due to mismatched expansion and probably incorrectly torqued bolts. A trip to the dealer who replaced the gasket and the car was still doing fine at 150,000 miles when I traded it in. I also hung a 427 aluminum intake maniford on an iron block 390 without any issues.

 

The 99-04 GTs have iron blocks and aluminum heads, as do the 03-04 Cobras. This is not a problem at all.