Gm Crate 350 /290 hp upgrading

[84calelky]

So instead of Hijacking the other thread I started a new one.
When I built the Elk I went with the Gm 350 290 crate motor , been a battle ever since to get it running right and still very unhappy with the Power (lack of)
So anyone thinking about doing this save yourself $$ and time and just drop an LS in 5.3 are inexpensive and you can get some serious power and still meet California strict SMOG laws.

so Here's my latest plan
Swap out the cast Iron 76cc heads for Edelbrock Performer RPM heads with 64 cc (bumps CR up)
use Felpro 1094 head gasket .015 thick calculated this (using Summits CR calc) plus heads should get 9.6 CR, great increase over the current 8.1 CR
Install Flowtech shorty smog legal headers (with air injection)
swap rear 3.08 gears to 3.42 limited slip .
parts budget $1950.00
Labor I am doing all the work .so basically free.

 

[84calelky]

So instead of Hijacking the other thread I started a new one.
When I built the Elk I went with the Gm 350 290 crate motor , been a battle ever since to get it running right and still very unhappy with the Power (lack of)
So anyone thinking about doing this save yourself $$ and time and just drop an LS in 5.3 are inexpensive and you can get some serious power and still meet California strict SMOG laws.

so Here's my latest plan
Swap out the cast Iron 76cc heads for Edelbrock Performer RPM heads with 64 cc (bumps CR up)
use Felpro 1094 head gasket .015 thick calculated this (using Summits CR calc) plus heads should get 9.6 CR, great increase over the current 8.1 CR
Install Flowtech shorty smog legal headers (with air injection)
swap rear 3.08 gears to 3.42 limited slip .
parts budget $1950.00
Labor I am doing all the work .so basically free.

I ran the out of Crate specs on DD5 (Desktop Dyno 5) then with my Upgrades .

 

[84calelky]

I ran the out of Crate specs on DD5 (Desktop Dyno 5) then with my Upgrades .
View attachment 180142

with Upgrades

 

[scoti]

So instead of Hijacking the other thread I started a new one.
When I built the Elk I went with the Gm 350 290 crate motor , been a battle ever since to get it running right and still very unhappy with the Power (lack of)
So anyone thinking about doing this save yourself $$ and time and just drop an LS in 5.3 are inexpensive and you can get some serious power and still meet California strict SMOG laws.

so Here's my latest plan
Swap out the cast Iron 76cc heads for Edelbrock Performer RPM heads with 64 cc (bumps CR up)
use Felpro 1094 head gasket .015 thick calculated this (using Summits CR calc) plus heads should get 9.6 CR, great increase over the current 8.1 CR
Install Flowtech shorty smog legal headers (with air injection)
swap rear 3.08 gears to 3.42 limited slip .
parts budget $1950.00
Labor I am doing all the work .so basically free.

About the LS....
I've read the LS swaps are only legal in CALI (on smog regulated vehicles) if you swap everything (EVERYTHING) that the donor vehicle had for it to be legal. Not sure Cali allows a Tahoe (Lt Truck) motor swap to a pass car. Verify that first.

For the current motor....
Have you researched using steel shim head gaskets on aluminum heads? I'd use the head gaskets recommended by Edelbrock for their aluminum heads.

What cam is used for the 290hp motor? Will the RPM heads volume be a mis-match & the E-Tech version be a better match?

 

[84calelky]

About the LS....
I've read the LS swaps are only legal in CALI (on smog regulated vehicles) if you swap everything (EVERYTHING) that the donor vehicle had for it to be legal. Not sure Cali allows a Tahoe (Lt Truck) motor swap to a pass car. Verify that first.

For the current motor....
Have you researched using steel shim head gaskets on aluminum heads? I'd use the head gaskets recommended by Edelbrock for their aluminum heads.

What cam is used for the 290hp motor? Will the RPM heads volume be a mis-match & the E-Tech version be a better match?

Yes Cali requires everything from the LS donor , Vehicle is then Smog tested as the donor Vehicle . Since the El camino is classified in California as a truck the 5.3 is allowed.

Here's where I got my Upgrade idea from . Part 2 has the heads swap .
Even though Edelbrock says to use their Head gasket I have found many people using shim style with success .

350/290 Crate Engine - Part 1

In Part 1 of this 350/290 crate engine build we show how you can pump in an extra 44hp and nearly 60 lb-ft of torque into it before we install new heads.

www.motortrend.com

350/290 Crate Engine - Part 2

For our Chevrolet Performance 350/290 "Great Crate" engine, a set of Edelbrock bolt-on aluminum cylinder heads and a rocker ratio swap was worth nearly 50 hp.

www.motortrend.com

 

[scoti]

Yes Cali requires everything from the LS donor , Vehicle is then Smog tested as the donor Vehicle . Since the El camino is classified in California as a truck the 5.3 is allowed.

Here's where I got my Upgrade idea from . Part 2 has the heads swap .
Even though Edelbrock says to use their Head gasket I have found many people using shim style with success .

350/290 Crate Engine - Part 1

In Part 1 of this 350/290 crate engine build we show how you can pump in an extra 44hp and nearly 60 lb-ft of torque into it before we install new heads.

www.motortrend.com

350/290 Crate Engine - Part 2

For our Chevrolet Performance 350/290 "Great Crate" engine, a set of Edelbrock bolt-on aluminum cylinder heads and a rocker ratio swap was worth nearly 50 hp.

www.motortrend.com

A 185cc head w/64cc chambers will definitely help the compression issue. Are you swapping the cam as well? The compression & flow of the heads will help regardless but you won't see the full potential w/o the cam timing events changing as well (to take advantage of the airflow/compression). Despite what others are doing.... I would stick to what Edelbrock recommends for THEIR heads. The slight gain in compression won't make that much difference w/o everything else being matched as well. But... that's just one guys opinion.

 

[84calelky]

A 185cc head w/64cc chambers will definitely help the compression issue. Are you swapping the cam as well? The compression & flow of the heads will help regardless but you won't see the full potential w/o the cam timing events changing as well (to take advantage of the airflow/compression). Despite what others are doing.... I would stick to what Edelbrock recommends for THEIR heads. The slight gain in compression won't make that much difference w/o everything else being matched as well. But... that's just one guys opinion.

Swapping the cam is a no go as it would screw the pooch Smog wise . I
I am not going for Big power just want to wake up this 350 .
Felpro 1094 forums say spray with copper spray if you're worried . I'll probably do it just to get the gremlin out of my head.

 

[Texas82GP]

What valve springs come on the Edelbrock heads? I think the E-techs come with dual springs which is a bit much for breaking in a flat tappet cam.

 

[84calelky]

What valve springs come on the Edelbrock heads? I think the E-techs come with dual springs which is a bit much for breaking in a flat tappet cam.

Motors was broke in about 3 years ago when I first installed this 350/290

 

[Texas82GP]

Motors was broke in about 3 years ago when I first installed this 350/290

Got it, you're keeping the original flat tappet cam. I'd just be cautious that the springs on the aftermarket heads are a good match (not too stiff) for that cam.