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use a cam out of 4.2 in 4.0
Posted: February 10th, 2012, 10:26 am
by jenmes70
if i use the the crank and rods out of a 1981 j10 in my 1996 grand why not the camshaft. it is my understanding that some stroker builders are basicaly useing that cam any way . im looking to do the poorest man stroker.i have a good 4.2 85 thousand miles on it and a used 4.0 with 109 miles want to strok it cheap with the old parts. not looking to race just a daily driver. just thought i read that and cant find it any more strker over load

Re: use a cam out of 4.2 in 4.0
Posted: February 10th, 2012, 7:42 pm
by IH 392
You can use the cam out of the 4.0, the cam out of the 258, if it's the stock one?, is a poor "smog" grind that's little more than a tent stake.
Re: use a cam out of 4.2 in 4.0
Posted: February 10th, 2012, 11:04 pm
by Retlaw01XJ
jenmes70 wrote:a used 4.0 with 109 miles want to stroke it cheap with the old parts. not looking to race just a daily driver. just thought i read that and cant find it any more stroker over load

Start with checking your lifters.... they must be matched to the cam lobe they came off of. If they are mixed up, buy new lifters. About $5 each.
If they are worn.... check with a straight edge... concave (gap in the center) means they need to be replaced. Convex (high in the center) they can be reused.
new stock (later)Cam + lifters = $180.
4.2 rods = stock pistons with a higher compression ratio. Unless you have them dished. $$.
4.0 rods = forged pistons for more $$.
Either option may require the block deck to be cut and more $$.
Plan ahead for EVERYTHING if a low-budget build is your goal.
Re: use a cam out of 4.2 in 4.0
Posted: February 11th, 2012, 11:49 am
by jenmes70
so is the 4.2 camshaft a better cam? than the 4.0 ?

Re: use a cam out of 4.2 in 4.0
Posted: February 11th, 2012, 7:33 pm
by IH 392
Guess that you were unable to interpret my previous statement?, NO, your 258 cam has nowhere near the performance potential of your 4.0 cam.