Head swap
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 22
Likes: 3
Head swap
I am considering replacing my stock 624 heads with Speedmaster 1-281-001-01 aluminum heads. My 350 motor is an L82. I would like to keep the original intake manifold and exhaust ram horn manifolds. I know that I need to change the pushrods to the 7.9" length and I am considering using roller tip rocker arms..... anyone here done this conversion? Any advice would be appreciated... thanks
Drifting
Joined: Jun 2025
Posts: 1,715
Likes: 597
I am considering replacing my stock 624 heads with Speedmaster 1-281-001-01 aluminum heads. My 350 motor is an L82. I would like to keep the original intake manifold and exhaust ram horn manifolds. I know that I need to change the pushrods to the 7.9" length and I am considering using roller tip rocker arms..... anyone here done this conversion? Any advice would be appreciated... thanks
Are ya gonna keep the L82 cam & lifters?
Speedmaster fka Procomp has lengthy & checkered-past. Maybe they're sugar now, maybe shyt ? dunno. Better choice is Trick Flow Specialties.
Burning Brakes
Joined: Dec 2017
Posts: 1,043
Likes: 414
2023 C3 of the Year Finalist - Modified
Just my two cents….
why go through the trouble of swapping heads when you plan to keep the restrictive intake and exhaust?
Are you trying to improve performance? Or are you just swapping heads to avoid having to rebuild the stock ones? The latter is understandable.
probably over $1k for what, 30-40hp gain?
you can delete the cat for under $100 and get the same result.
why go through the trouble of swapping heads when you plan to keep the restrictive intake and exhaust?
Are you trying to improve performance? Or are you just swapping heads to avoid having to rebuild the stock ones? The latter is understandable.
probably over $1k for what, 30-40hp gain?
you can delete the cat for under $100 and get the same result.
Thread Starter
Heel & Toe
Joined: Oct 2024
Posts: 22
Likes: 3
I am not looking for any extra power/performance particularly but just to replace the existing heads which we know are pretty dire......if anyone on here can give me any recommendations that would be appreciated.... thanks guys
Burning Brakes
Joined: Oct 2012
Posts: 1,152
Likes: 252
many, many years ago I swapped to GM 128 aluminum heads on my 69 ZQ3 when the original heads were in need of attention. The swap was very strait forward. Just make sure the block deck surface is clean and flat. I used the factory 1990/91 L98 MLS headgasket @ .028". The swap got me a huge weight loss, higher compression and thus more low rpm torque with the smaller 58 cc chambers, and hardened valve seats so no more lead substitute. Still on the car to this day.
Burning Brakes
Joined: Dec 2017
Posts: 1,043
Likes: 414
2023 C3 of the Year Finalist - Modified
Ive used edelbrock estreet #5089 several times along with trick flow.
It is very likely you will need .1” longer hardened pushrods, you can buy a pushrod length checker tool.
I personally don’t think the roller rocker arms are worth it on a mostly stock motor. A properly setup stamped steel rocker set will last you many many miles.
Melting Slicks
Joined: Apr 2021
Posts: 2,711
Likes: 2,160
From: Minnesota
I took the gamble on Flowtek heads on my L48 with the understanding that they’ll be temporary before an entire engine swap. Two years later I haven’t had any issues, but like the Speedmasters they’re a foreign casting that’s assembled in the US, allegedly. If you only plan on doing this once I would look into some of the brands that are known quality and have better customer support if you run into problems.
Here is something to consider. Blueprint engines will sell you just the cylinder heads they put on their engines. The runner size is a bit on the big side for a stock L82, but it will give you plenty of room to grow if you decide to do other engine modifications in the future, and will be leagues better than the heads you’ll be taking off.
Here is something to consider. Blueprint engines will sell you just the cylinder heads they put on their engines. The runner size is a bit on the big side for a stock L82, but it will give you plenty of room to grow if you decide to do other engine modifications in the future, and will be leagues better than the heads you’ll be taking off.
Last edited by Piersonpie; Sep 11, 2025 at 06:54 PM.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
A couple of thoughts. I rebuilt my OEM L-82 completely in 2014, reconditioning the L-82 OEM connecting rods, reconditioning the forged L-82 crankshaft, Po rted the OEM L-82 intake, new 9:1 JE Forged Racing pistons, Howard Roller cam .525 lift/LSA 110/duration 219/225, and most importantly, for your cylinder head question (L-82 cast iron heads are 882's BTW), the only head to consider IMO if you plan on doing this once, AFR 180 64 CC heads which are hands down superior to just about anything else on the market, by a big margin. I also reused my Holley 4175 650 CFM spreadbore, comp cams roller 1.5 tipped rockers, with a 1 7/8 inch LTH headers with 2.5 inch duals, and Borla Type S C4 custom fitted mufflers
My L-82 355 makes about 450-460 Gross HP now, pretty much untouchable by any SBC Gen 1 motor.
My L-82 355 makes about 450-460 Gross HP now, pretty much untouchable by any SBC Gen 1 motor.
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Pro
Joined: Nov 2023
Posts: 703
Likes: 335
From: Aubrey TX
I did this swap 18 months ago on a 73 L82. I used the Edelbrock e-Street heads and the Crane roller tip rockers 1.5:1 I think. I used new (longer) push rods and new lifters but everything else remained stock. The e-Street heads dont have the exhaust crossover for the intake and they dont play nice with roller cams.
If I were to do it again, I would go with similar closed chamber aluminum heads but ones that have the crossover port and roller cam ready.
If I were to do it again, I would go with similar closed chamber aluminum heads but ones that have the crossover port and roller cam ready.
Burning Brakes
Joined: Dec 2017
Posts: 1,043
Likes: 414
2023 C3 of the Year Finalist - Modified
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
There are four things in a man's life that are grossly overestimated:
Size of their bratwurst.
The fish that snapped a line.
Annual income, without IRS looking.
The H.P. of a rebuilt engine.
Old Pro Solo Guy
Joined: Dec 2017
Posts: 8,090
Likes: 4,446
From: Marlton NJ
If you are keeping the stock pistons, I would get the smallest chamber size you can get, to increase the compression as much as possible.
The stock 9:1 is very low. Emission era.
Multiple TQ & HP benefits.
I think it is Trickflow and maybe some others that have 58cc heads.
The stock 9:1 is very low. Emission era.
Multiple TQ & HP benefits.
I think it is Trickflow and maybe some others that have 58cc heads.
Melting Slicks
Joined: Jul 2006
Posts: 2,291
Likes: 492
From: Salmon Arm, BC
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
Right now... these are the best value for budget performing heads. they are th same castings as the flotek heads there are some you tube videos reviewing them. if you do get them, depending on the cam your running I would swap the springs.
https://www.vevor.com/cylinder-heads...hoCq2cQAvD_BwE
https://www.vevor.com/cylinder-heads...hoCq2cQAvD_BwE
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
I was asked to comment about my heads and combo by another forum member that saw this thread but I forgot why I walked away from the C3 forum for a number of years, until most recently.
Thanks, Gentlemen, for the reminder, for me not to bother any more, moving forward on certain threads. No problem.
Enjoy...............
Thanks, Gentlemen, for the reminder, for me not to bother any more, moving forward on certain threads. No problem.
Enjoy...............
Last edited by jb78L-82; Sep 12, 2025 at 05:23 PM.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,212
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
With ALL heads, you get what you pay for
Le Mans Master
Joined: May 2007
Posts: 5,028
Likes: 1,120
From: North tonawanda NY
There is truth to that.. to a point. but flow and performance tests between the heads I linked above and the brodix heads they area clone of resulted in the opposite with the chinese vevor/flotek heads actually outperforming the identically sized version brodix heads. Im sure there are better quality valves and guides out there and for some the additional cost for that hardware will pay off but not for everyones situation and when compared to the stock heads and hardware they are still an upgrade. The thing is, With heads and many performance auto parts its a shell game with white box generic parts being repackaged and rebranded and marked up accordingly so you dont always get what you pay for.
I bought a different set of bare chinese castings and loaded them myself with brand name hardware for about $750 and they work well on my engine. I cant brag about having $2000 heads but I dont care too either. Of course I could have also bought the exact same castings I have now from AFR... If I didnt want to learn how to assemble and set them up myself I would have. Today? Id buy the vevor heads and replace the springs and maybe seals.
I bought a different set of bare chinese castings and loaded them myself with brand name hardware for about $750 and they work well on my engine. I cant brag about having $2000 heads but I dont care too either. Of course I could have also bought the exact same castings I have now from AFR... If I didnt want to learn how to assemble and set them up myself I would have. Today? Id buy the vevor heads and replace the springs and maybe seals.
Drifting
Joined: Jun 2025
Posts: 1,715
Likes: 597
Castings are one thing, But
More often than not, broken valvetrain parts n pieces leads to wrecked motors.
Unless you've got the inside straight and just won a big lotto, don't run no-name Asian valvetrain that's priced too-good-to-be-true.
If you win a valvetrain gamble, that'll be sweet ! But, if you don't
More often than not, broken valvetrain parts n pieces leads to wrecked motors.
Unless you've got the inside straight and just won a big lotto, don't run no-name Asian valvetrain that's priced too-good-to-be-true.
If you win a valvetrain gamble, that'll be sweet ! But, if you don't
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
The problem in the aftermarket parts world is too many companies using a common / likeness name.
This adds to misinformation / mistaken identity.
For example:
ProComp
ProFlex
ProForm
ProFlow
ProTech
ProMaxx
Should one, just one, of the above parts fail, they all may get bad feedback.
For example again:
Social Media says that Pro-somethings are no good.
Internet says Pro-somethings are awesome.
I am not a big fan of spending $2,000 on heads just for cruising the streets. Money NOT well spent.
A wise man says with anything priced from dangerously low to outragesly high:
Pick in the middle.
This adds to misinformation / mistaken identity.
For example:
ProComp
ProFlex
ProForm
ProFlow
ProTech
ProMaxx
Should one, just one, of the above parts fail, they all may get bad feedback.
For example again:
Social Media says that Pro-somethings are no good.
Internet says Pro-somethings are awesome.
I am not a big fan of spending $2,000 on heads just for cruising the streets. Money NOT well spent.
A wise man says with anything priced from dangerously low to outragesly high:
Pick in the middle.