Jeep Strokers

I have a 99 cherokee I plan on building a stroker for. I was told that the 87-90 blocks were the best for stroking and you could use a 0630 head on them. Is this true? I have a lead on a donor vehicle that is an 89 and Id like to be sure I am doing the right thing before I pick it up.

Your 99 block is what I would use. If it has the cam retaining plate switching to the pin and spring will open up a much larger range of camshafts.

And yes the heads will interchange.

A 4.0L block of any year will do fine for a stroker build. If I was in your shoes I'd build up the '89 XJ donor into a stroker short block with an aftermarket performance cam, and bolt on the '99 head plus all the '99 ancillaries.

Why ?

Has it ever been definitively proven the RENIX blocks are better ? If so then better then what ?.

I was told the walls are thicker and it has more zinc I believe it was in the metal. If there is a better year I can wait and find one of a particular year. Was just curious if one year is better then another or they are all the same.

Yet to see proof of a thicker casting. Even if so, so what ?
All the blocks will go +60 and I've built a number of +80's out of OBD1 era blocks.

Zinc is a soft metal. You don't want zinc mixed in your casting pour anymore then you need to. There are better choices of ingredients to choose from. Nickel as an example when blended into the mix offers a bit more hardness.

But again unless your building some odd variant run what you have.

Thanks for the info

The nickel content is supposedly higher j.

jsawduste wrote:Yet to see proof of a thicker casting. Even if so, so what ?
All the blocks will go +60 and I've built a number of +80's out of OBD1 era blocks.

Exactly, and I think the OP meant a higher nickel content in the Renix blocks though I haven't seen any evidence to back that up. AFAIK, all the 4.0L blocks have a high nickel content and that's why they're so durable.

Thanks for the help. I finally looked at it today. The block has a fair amount of rust on it. The oil pan doesn't look rusted through and the floorboards and the rest of the jeep seem ok. Is the rust on the block a cause for concern or is it normal for the age?

Also it doesnt run, was told starter is bad. Does that matter as Im ripping it apart anyway.

All and all if ok I will pick it up Saturday.

I wouldn't be too worried about the outside of the block.
As long as the engine was sealed up and nothing got in through the throttlebody you should be fine.

If you use an HO block instead of your renix block you will need to drill and tap a couple holes on the driver's side of the block to accommodate the ping and other sensors . See my build up for details.

My feelings on what would be the best block are fairly simple. It would be an NVH block. It has more material in the main web area and it has the built in main girdle. The whole idea behind the block was a factory re-design that dealt with the Noise, Vibration, & Harmonics normally associated with a straight 6. Hence the NVH moniker. I sought one out for my build and would do so again. It always makes sense to use the best foundation available and I believe that to be the NVH block. They are plentiful.