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Old 08-21-2025 | 07:59 PM
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Default Which cam???

Hello all.
rebuilding a Gen V 454 EFI engine.
stock everything except .30” over pistons.
exhaust and everything will remain the same.
wet exhaust.
which current cam would match the specs of the factory 1995 385hp 454 EFI cam that was in my engine or come closest?
Don’t want to get radical or worry about reversion and really don’t want to go smaller as I don’t want to lose hp.
thanks.
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Old 08-22-2025 | 07:43 AM
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Are you converting to a hydraulic roller cam or are you gonna attempt to install another flat tappet hydraulic?
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Old 08-22-2025 | 08:36 AM
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Flat tappet hydraulic
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Old 08-22-2025 | 09:06 AM
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Originally Posted by Tom272Baja
Flat tappet hydraulic
have you installed a flat tappet hydraulic in last 10 years, between lifter quality, cam cores etc I WONT do it at my shop, I'd tell you to reconsider unless you can find something real old nib and same w lifters. Local guy who also builds engines has had a 30 to 50% failure rate in past couple years even with fanciest lifters you can buy, lots of zinc, breaks in on outer springs, the whole deal
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Old 08-22-2025 | 09:55 AM
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I have not to be honest.
what would be involved in changing up to something more up to date reliable?
do you have a cam you could recommend that won’t break the bank?
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Old 08-22-2025 | 10:14 AM
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What Smitty said!

A flat tappet will most likely lead to premature destruction and another complete teardown, clean-up, and rebuild.

A suggestion would be to find a stock replacement Gen VI roller for real cheap (someone may have one on here... post in the "parts wanted" sub forum - they may even give it away), use a GM Gen VI timing set (comes with the retainer plate and bolts), and then your choice of a good set of link-bar roller lifters.

Specs on the MPI cam (from posts back in the day):

288*/288* seat
224*/224* @.050"
.483"/.483" valve
115.5* LSA
109* ICL
122* ECL

Springs:

1.487"
110# @ 1.88" installed
261 # nose
316# rate

As you can tell, the specs are very mild. This should be compatible with your current EFI setup (others I'm sure will chime in to confirm).

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Old 08-22-2025 | 03:04 PM
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Attesting to the above. In my eyes flat tappet is dead, too many failures recently, my rebuilds included. Bite the bullet and go roller, you will also enjoy a boost in HP curves too
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Old 08-22-2025 | 07:46 PM
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Had no idea they built EFIs with out rollers!
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Old 08-23-2025 | 05:54 AM
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Originally Posted by hogie roll
Had no idea they built EFIs with out rollers!
Its strange how some engines youd think would or should have had them dont. The 1986 to 1995 5.7 is same way, 1 piece crank seal, certain ones got hyd rollers, trucks and boats did not but like the Gen V BBC, at least they have provisions for the spider hold down for dog bone lifters.
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Old 08-23-2025 | 12:03 PM
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Originally Posted by articfriends
Its strange how some engines youd think would or should have had them dont. The 1986 to 1995 5.7 is same way, 1 piece crank seal, certain ones got hyd rollers, trucks and boats did not but like the Gen V BBC, at least they have provisions for the spider hold down for dog bone lifters.
Yeah I’ve got an 88 K5 that would have originally had TBI but I was surprised it has flat tappets.

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