08 Silverado 5.3 pushrod length
01-14-2017, 09:30 PM
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08 Silverado 5.3 pushrod length
Going to do a dod delete with new cam ( comp cam 54-450-11) new to the LS engines . Want to know if there is a standard pushrod length or where to start.
01-15-2017, 03:35 AM
#2
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Your best bet is to buy a pushrod length checker, such as COMP Cams 7702 Adjustable Pushrod Length Checker.
Now Stock Pushrods measure out at 7.375" exactly on a Gen4 5.3 (At least on my Iron Block LMG 5.3 engine). I had a local engine machine shop use a "Pushrod Measuring Caliper" to know for sure since I was told they are 7.400" and looking it up under the part number says 7.325". I literally just measured mine last week and ordered some up.
I had my heads milled and used a thinner head gasket, also I am using a BTR Truck Stage 2 Cam. I came up with 7.325" for my pushrod length after adding 0.075 preload.
Also, most of Comp's cams have a base circle that is about 0.050 smaller, so you would need to add 0.025 to your pushrod length. Now this number may vary and this is why it is always best to measure.
If you are using stock head gaskets with no machine work to your heads or block, you will more than likely end up with a 7.400" Pushrod, if not stock length 7.375". But like I said, it is best to measure since no 2 engines are identical. Also preload will vary depending on which lifter you are using. If you are switching out all lifters to LS7 ones (8 of your stock lifters are LS7 Lifters), GM recommends 0.082 Preload. 0.47-0.94 of preload is the acceptable range.
Now Stock Pushrods measure out at 7.375" exactly on a Gen4 5.3 (At least on my Iron Block LMG 5.3 engine). I had a local engine machine shop use a "Pushrod Measuring Caliper" to know for sure since I was told they are 7.400" and looking it up under the part number says 7.325". I literally just measured mine last week and ordered some up.
I had my heads milled and used a thinner head gasket, also I am using a BTR Truck Stage 2 Cam. I came up with 7.325" for my pushrod length after adding 0.075 preload.
Also, most of Comp's cams have a base circle that is about 0.050 smaller, so you would need to add 0.025 to your pushrod length. Now this number may vary and this is why it is always best to measure.
If you are using stock head gaskets with no machine work to your heads or block, you will more than likely end up with a 7.400" Pushrod, if not stock length 7.375". But like I said, it is best to measure since no 2 engines are identical. Also preload will vary depending on which lifter you are using. If you are switching out all lifters to LS7 ones (8 of your stock lifters are LS7 Lifters), GM recommends 0.082 Preload. 0.47-0.94 of preload is the acceptable range.