Wanting some opinions...
09-26-2013, 11:47 PM
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Wanting some opinions... Not the sexiest build... yet... but I want some "educated" opinions...
Donor truck: 1992 Chevrolet extended cab 2wd. Sentimental value... It was my grandfather's truck...
I purchased what I thought was a 2007 gen4 5.3 and 4l65e with about 40k miles for a whopping $500. The year, mileage, and trans were all correct, but the engine turned out to be a 4.8... I didn't want to spend the money to freshen up the 4.8, so I hunted down a 3.62 crank and 6.098 rods and planned to re-use the 4.8 pistons to make a high c/r 5.3. An iron L33, if you will. Come to find out, the 799 heads that came on the engine have larger chambers and the c/r wont be as high as I thought. Not a big deal. Well, I then discovered that the gen4 connecting rods had floating wrist pins... The 6.098 rods I bought were from an LS1... Pressed pins... Can't use the rods with the 4.8's pistons... My budget for this portion of my OBS Chevy build is not very big... Sooooooo
My options are as follows:
Rebuild the 4.8 and eat the money I spent on crank and rods - $175 (possibly re-sell crank and rods)
Bore the gen4 block to 5.7 and use the crank and rods/pistons - $240 to bore
Buy a guy's LS2 floating pin rods and make the 5.3 with the 4.8 pistons - $200 for the mint rods and bearings. (is that too much to pay for like new LS2 rods and bearings?)
I will end up spending the same amount of money for the rest of the re-build and the cost difference in the three above options is negligent.
My plans are to cam, stall, and 150 shot the engine some time after Christmas... What option would I be most happy with? I'm leaning towards the iron 5.7 because there is no replacement for displacement, but I'm a little worried about the durability of the cylinder walls after a .118 over bore...
Sorry the post is so long, just trying to lay it all out there...
Any thoughts or advise would be appreciated.
Donor truck: 1992 Chevrolet extended cab 2wd. Sentimental value... It was my grandfather's truck...
I purchased what I thought was a 2007 gen4 5.3 and 4l65e with about 40k miles for a whopping $500. The year, mileage, and trans were all correct, but the engine turned out to be a 4.8... I didn't want to spend the money to freshen up the 4.8, so I hunted down a 3.62 crank and 6.098 rods and planned to re-use the 4.8 pistons to make a high c/r 5.3. An iron L33, if you will. Come to find out, the 799 heads that came on the engine have larger chambers and the c/r wont be as high as I thought. Not a big deal. Well, I then discovered that the gen4 connecting rods had floating wrist pins... The 6.098 rods I bought were from an LS1... Pressed pins... Can't use the rods with the 4.8's pistons... My budget for this portion of my OBS Chevy build is not very big... Sooooooo
My options are as follows:
Rebuild the 4.8 and eat the money I spent on crank and rods - $175 (possibly re-sell crank and rods)
Bore the gen4 block to 5.7 and use the crank and rods/pistons - $240 to bore
Buy a guy's LS2 floating pin rods and make the 5.3 with the 4.8 pistons - $200 for the mint rods and bearings. (is that too much to pay for like new LS2 rods and bearings?)
I will end up spending the same amount of money for the rest of the re-build and the cost difference in the three above options is negligent.
My plans are to cam, stall, and 150 shot the engine some time after Christmas... What option would I be most happy with? I'm leaning towards the iron 5.7 because there is no replacement for displacement, but I'm a little worried about the durability of the cylinder walls after a .118 over bore...
Sorry the post is so long, just trying to lay it all out there...
Any thoughts or advise would be appreciated.
09-28-2013, 04:24 PM
#4
I built essentially the same motor as you are describing, a 5.3HO with the flat top pistons. I was lucky to find some take out LS3(or maybe LS6) rods for $120 without the bearings. Used LS1 heads milled down .025 to get the c/r to 10.25-1 and a takeout Z06 camshaft. You already have the crank so why not buy the rods. You should have everything balanced, so keep that in mind as it typically costs $2-300. LS1 heads are cheap and the milling cost less than $100. This combo makes for a reasonably priced 350hp motor. It can be done for less than $2000 including the donor motor.