12 valve or 24 valve
#11
#12
RE: 12 valve or 24 valve
Regardless of the 12 valve or the 24 valve, the one ting you probably want to keep your eye on is the block number. The 53 block on the 24 valve has caused some people some problems. I'd watch out for that more than anything else.
#14
RE: 12 valve or 24 valve
I swear I just posed some info on this in this thread. . .where did my post go[&:]
anyway, the 53 block cast in brazil has a slight casting defect on the exhaust side of the block that can cause a crack in the water jacket. if you crawl under the truck and look at the front of the engine just above the oil pan you will see in pretty big numbers '53'. if you see something else you have a mexican cast block that for some reason tips the scales as the heaviest casting for any ISB block.
this only applies to trucks produced from 99-01
anyway, the 53 block cast in brazil has a slight casting defect on the exhaust side of the block that can cause a crack in the water jacket. if you crawl under the truck and look at the front of the engine just above the oil pan you will see in pretty big numbers '53'. if you see something else you have a mexican cast block that for some reason tips the scales as the heaviest casting for any ISB block.
this only applies to trucks produced from 99-01
#18
#19
RE: 12 valve or 24 valve
To tell you the truth I really don't know. It had the exhaust when I bought it and I never really looked at the down tube. I'm about to crawl under it tonite and patch a hole in the exhaust so I'll look at it. My guess is that your exhaust shop isn't wrong and that the exhaust is around 4" at the manifold and then expands to the full 4.5" after. In short its huge and its LOUD.
#20