5.0 to 5.7 swap
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Joined: Jun 2008
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From: Riverside Ca
Car: 1987 z28
Engine: 305tpi
Transmission: 700r4
Axle/Gears: 2.73 posi
5.0 to 5.7 swap
Well the good old 305 has a blown head gasket, leaks oil, and is too slow for me, so time for the classic 350 swap.
I pulled the 350 out of a 95 or 96 2500 suburban. It had flat tappet but its a roller ready block, with the retainer holes tapped.
The casting is 10243880 which after looking it up its a
10243880...350...95-00...2 or 4...Vortec truck, Gen.I crate motors and "ZZ4", roller cam, one piece rear seal
Tore it down and its a 2 bolt, but it does not have a roller cam.
The cam thats going in (as stated by the seller)
" The
advertised valve lift for this particular cam is .459 and the
advertised duration being 270 degrees, at .050 the dur. is 210 degrees.
The lobe separation for this cam is at 112 degrees. This cam is a nice
street cam, good for mild performance w/slightly noticable lope at
idle. The best operating range for this cam is between 1500-5500 rpm.
It will work with stock torque converter. You should be able to use the
stock valve train. This cam will work with a stock computer."
I plan for this to be a close to stock build. I will be using the stock 305 heads and TPI.
It has 24lb injectors, magnaflow cat and flowmaster cat back.
Whats a good estimate on the numbers this set up will put down?
is 280+hp and 350+tq at the fly wheel achievable?
I pulled the 350 out of a 95 or 96 2500 suburban. It had flat tappet but its a roller ready block, with the retainer holes tapped.
The casting is 10243880 which after looking it up its a
10243880...350...95-00...2 or 4...Vortec truck, Gen.I crate motors and "ZZ4", roller cam, one piece rear seal
Tore it down and its a 2 bolt, but it does not have a roller cam.
The cam thats going in (as stated by the seller)
" The
advertised valve lift for this particular cam is .459 and the
advertised duration being 270 degrees, at .050 the dur. is 210 degrees.
The lobe separation for this cam is at 112 degrees. This cam is a nice
street cam, good for mild performance w/slightly noticable lope at
idle. The best operating range for this cam is between 1500-5500 rpm.
It will work with stock torque converter. You should be able to use the
stock valve train. This cam will work with a stock computer."
I plan for this to be a close to stock build. I will be using the stock 305 heads and TPI.
It has 24lb injectors, magnaflow cat and flowmaster cat back.
Whats a good estimate on the numbers this set up will put down?
is 280+hp and 350+tq at the fly wheel achievable?
Thread Starter
Member
iTrader: (2)
Joined: Jun 2008
Posts: 166
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From: Riverside Ca
Car: 1987 z28
Engine: 305tpi
Transmission: 700r4
Axle/Gears: 2.73 posi
Re: 5.0 to 5.7 swap
so using desktop dyno03 it said this (see attatched pic) not bad actually. bassically a stock build with a cam.
now i have a problem, the cam is a roller, now that seal in the back of the block, how far does that get pushed in? is the cam supposed to rest on that? Or does the cam gear get all the load?
now i have a problem, the cam is a roller, now that seal in the back of the block, how far does that get pushed in? is the cam supposed to rest on that? Or does the cam gear get all the load?

Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
The rear cam bearing plug is just installed until the outer lip is flush with the block.
The cam gear takes the thrust.
The cam gear takes the thrust.
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
By the way, roller lifters use shorter pushrods than flat tappets. So, the seller's statement about using the stock valve train is only true if you use the TPI stuff. A Vortec engine should have had a roller cam, I suspect your engine was a late '95 truck block. Shouldn't matter as long as the roller lifter provisions have been machined.
Thread Starter
Member
iTrader: (2)
Joined: Jun 2008
Posts: 166
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From: Riverside Ca
Car: 1987 z28
Engine: 305tpi
Transmission: 700r4
Axle/Gears: 2.73 posi
Re: 5.0 to 5.7 swap
im using all the stock tpi valvetrain, and the new block is roller ready. cant wait to fire her up. oh the anxiety lol
any tips are welcomed, its my first build so you experienced guys please chime in
I appreciate your help!
any tips are welcomed, its my first build so you experienced guys please chime in

I appreciate your help!
Thread Starter
Member
iTrader: (2)
Joined: Jun 2008
Posts: 166
Likes: 0
From: Riverside Ca
Car: 1987 z28
Engine: 305tpi
Transmission: 700r4
Axle/Gears: 2.73 posi
Re: 5.0 to 5.7 swap
how do i get those pesky motor mount bolts off? the engine is done but i need to swap those out.

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Thread Starter
Member
iTrader: (2)
Joined: Jun 2008
Posts: 166
Likes: 0
From: Riverside Ca
Car: 1987 z28
Engine: 305tpi
Transmission: 700r4
Axle/Gears: 2.73 posi
Re: 5.0 to 5.7 swap
Well she started and i got her to run...somewhat. I have the stock 305tpi chip, 24lb injectors and the 350 knock sensor. the computer cannot find where to idle. driving its fine, sometimes it tugs a bit. engine shakes a bit. i know it needs to be tuned to run great but is there anything im missing to have it drivable for a while?
Thread Starter
Member
iTrader: (2)
Joined: Jun 2008
Posts: 166
Likes: 0
From: Riverside Ca
Car: 1987 z28
Engine: 305tpi
Transmission: 700r4
Axle/Gears: 2.73 posi
Re: 5.0 to 5.7 swap
im not sure, i know sooner or later my tranny and rear will blow. specially after the break in with a few WOT runs lol.
well i think its a spark problem. i was checking the timing again, and the light was not flashing steady. i checked all the wires with the inductive pick up. . a few were constant and steady and some would fire here and there. so this must be coil pickup/ignition control module problem?
well i think its a spark problem. i was checking the timing again, and the light was not flashing steady. i checked all the wires with the inductive pick up. . a few were constant and steady and some would fire here and there. so this must be coil pickup/ignition control module problem?
Thread Starter
Member
iTrader: (2)
Joined: Jun 2008
Posts: 166
Likes: 0
From: Riverside Ca
Car: 1987 z28
Engine: 305tpi
Transmission: 700r4
Axle/Gears: 2.73 posi
Re: 5.0 to 5.7 swap
ok, swapped those out and now it idles much smoother. A few surges here and there. mostly when stopped at a light or in 3rd gear at 1000rpm if i let off the gas it tugs alot
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