Need diagnosis help- Vortec 350
03-05-2012 | 07:19 AM
#11
If it's from a 96 that still had the stock PCM and CSFI even tuned it couldn't rev over 5900 rpm....... that's all the black box computers in those trucks will allow. You can set the limiter to 8000 rpm if you want.... and it still shuts down at 5900. Is that enough to bend pushrods on the stock cam? Maybe, if it was sustained long enough I guess. Valve springs all okay?
Either way with a Vortec carbed intake, TBI adapter and then whatever else you plan it will run way harder than an L05 can!
Either way with a Vortec carbed intake, TBI adapter and then whatever else you plan it will run way harder than an L05 can!
03-05-2012 | 07:20 PM
#13
Staging Lane
Joined: Sep 2011
Posts: 71
Likes: 0
From: nj
i bet you 1k it came out of a "mud truck".Got burried and probably just held it to the floor.I had a full bolt on LO5 and it still wasnt enough,The truck will rev to 5900 but the stock valve springs are only good to 5k.
03-05-2012 | 07:53 PM
#14
I use this as a guideline and it is accurate. My 92 had the 148 flat tappet only block in it.... And no I didn't write it originally, just coincidental the OP and I had the same year truck as an example, lol.
One thing- not ALL the '87-up blocks are provisioned for roller cams. I have a '92 truck 5.7L engine w/swirl port TBI heads and NO bosses for the spider, no machined lifter bosses, no cam retainer bosses, etc. Not just untapped- un-there! lol
The breakdown goes like this (be aware there are ALWAYS exceptions):
For 350 flat tappet blocks look for casting number 10054727, 14079287, 14088548, and 14101148.
For 350 roller tappet blocks look for casting numbers 10243880, 14011148, 14088526, and 14093638.
There are '87-up blocks that have the full provisions for a mechanical fuel pump, but they're relatively rare. Most often they're the earlier blocks and blocks that are equipped w/flat tappet cams.
Something to watch out for: There's a flat tappet block AND a roller block that both end with the numbers 148. 14101148 is a flat tappet block, 14011148 is a roller block.
About the quickest way to tell if you are looking at a roller engine in the junk yard, is to pull a valve cover and remove a push rod. Flat tappet p-rods are about 7.8”, roller p-rods are much shorter at 7.2” long.
AFAIK, there's no 'good' and 'not as good' blocks, other than 2- and 4-bolt mains.
Hope this helps!
The breakdown goes like this (be aware there are ALWAYS exceptions):
For 350 flat tappet blocks look for casting number 10054727, 14079287, 14088548, and 14101148.
For 350 roller tappet blocks look for casting numbers 10243880, 14011148, 14088526, and 14093638.
There are '87-up blocks that have the full provisions for a mechanical fuel pump, but they're relatively rare. Most often they're the earlier blocks and blocks that are equipped w/flat tappet cams.
Something to watch out for: There's a flat tappet block AND a roller block that both end with the numbers 148. 14101148 is a flat tappet block, 14011148 is a roller block.
About the quickest way to tell if you are looking at a roller engine in the junk yard, is to pull a valve cover and remove a push rod. Flat tappet p-rods are about 7.8”, roller p-rods are much shorter at 7.2” long.
AFAIK, there's no 'good' and 'not as good' blocks, other than 2- and 4-bolt mains.
Hope this helps!
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