Edelbrock top end kits
Thread Starter
Instructor
Joined: Apr 2018
Posts: 165
Likes: 92
From: Buxton ME
Edelbrock top end kits
Anyone have any experience with the Edelbrock top end kits? Doing some research on the same old question, upgrade the original motor or go crate. Car is all original 1977 L48, runs great, just slow.
Thanks for any feedback.
Thanks for any feedback.
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
I can't provide sources, but I have seen several dyno tests on the Edelbrock top end kits, and the numbers that Edelbrock brags about seem to be fairly accurate on a fresh bottom end.
Scotty
Scotty
Pro
Joined: Jun 2021
Posts: 505
Likes: 230
There are lots of options besides edelbrock, but nothing against edelbrock kits. First thing is check your compression and make sure it's worth putting a top end on. There are people on here that can guide you on proven combo's depending on your transmission and gears.
I did the brodix IK 180's with a Comp HE268 on my 77 L48 auto with 3.08's, it was better than stock but still not enough fun for me. I'm now running a mid 400's HP roller 383 with a 700r4 and 3.70 gears and it's now fun to drive. I wish I had just skipped ahead to a 383 with at least 400 HP instead of trying to upgrade the L48.
I did the brodix IK 180's with a Comp HE268 on my 77 L48 auto with 3.08's, it was better than stock but still not enough fun for me. I'm now running a mid 400's HP roller 383 with a 700r4 and 3.70 gears and it's now fun to drive. I wish I had just skipped ahead to a 383 with at least 400 HP instead of trying to upgrade the L48.
Race Director
Joined: Nov 2006
Posts: 13,256
Likes: 7,844
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Truthfully, the L48 can be upgraded successfully within limits. It is a 2 bolt main block. basic crank and rods.
Not L82 stuff. But still very capable of 350 HP.
Biggest limiting factor is the dished pistons.
Replace pistons with flat tops. use a. 015 head gasket if you are not decking the block.
Then with the Edlebrock heads, you can see some increase in power .
Rear end gearing. Huge!
If your car is an Automatic. (God help you). You will likely have a horrible ratio 3.08 -1 I think. absolutely horrible for any kind of acceleration.
Not L82 stuff. But still very capable of 350 HP.
Biggest limiting factor is the dished pistons.
Replace pistons with flat tops. use a. 015 head gasket if you are not decking the block.
Then with the Edlebrock heads, you can see some increase in power .
Rear end gearing. Huge!
If your car is an Automatic. (God help you). You will likely have a horrible ratio 3.08 -1 I think. absolutely horrible for any kind of acceleration.
Burning Brakes
Joined: Dec 2017
Posts: 1,043
Likes: 414
2023 C3 of the Year Finalist - Modified
I used an edelbrock top end kit when I rebuilt my motor and It turned out great. For me it was hard to beat the value, at the time edelbrock was offering a free carb with purchase of the top end kit. Assembly was a breeze, no issues. The instructions are very clear if you happen to be new to mechanical work.
I used the estreet kit part # 2022. I did however go with a different cam, the performer cam is kinda mild. I went with edelbrock torker plus cam. Went with 650 AVS2 carb.
I did do before and after dynos, but I also changed the exhaust at the same time. I would recommend that regardless of what heads you buy. There’s no point in buying better heads if the flow is still corked by an overly restrictive exhaust! But before dyno 153rwhp, after rebuild dyno, 276 rwhp/326rwtq.
very noticeable difference driving around town.
edelbrock says 315 crank HP for the 2022 kit, I think I’m around 330 or so, probably from using a bigger cam.
like everyone, I wish it still had more power. I ended up getting a 125 shot NOS and it’s a lot of fun.
I used the estreet kit part # 2022. I did however go with a different cam, the performer cam is kinda mild. I went with edelbrock torker plus cam. Went with 650 AVS2 carb.
I did do before and after dynos, but I also changed the exhaust at the same time. I would recommend that regardless of what heads you buy. There’s no point in buying better heads if the flow is still corked by an overly restrictive exhaust! But before dyno 153rwhp, after rebuild dyno, 276 rwhp/326rwtq.
very noticeable difference driving around town.
edelbrock says 315 crank HP for the 2022 kit, I think I’m around 330 or so, probably from using a bigger cam.
like everyone, I wish it still had more power. I ended up getting a 125 shot NOS and it’s a lot of fun.
Thread Starter
Instructor
Joined: Apr 2018
Posts: 165
Likes: 92
From: Buxton ME
Thanks for responses. The motor has 90,000 miles on it, but surprisingly it makes 180 to 200 psi all around on a compression test. It's a 4-speed car with a fresh tranny rebuild and 3.36 gears.
So, if I'm just shooting for 325 hp/375 tq, I might get away with the iron Vortec heads, the Edelbrock intake and something like a Lunati Voodoo cam (219/227)? I have this cam in my '64 Lemans 326 with modified heads and a Quickfuel 450 and it makes 325/380.
I am tempted by the 383 crate motors, but the damn motor/bell housing/tranny are so tightly packed in, I thought I'd try to get by with top end work. I've had the motor in and out of the Lemans three times, but there's so much room to work with there. I'll do up the costs and see how the total project works out.
So, if I'm just shooting for 325 hp/375 tq, I might get away with the iron Vortec heads, the Edelbrock intake and something like a Lunati Voodoo cam (219/227)? I have this cam in my '64 Lemans 326 with modified heads and a Quickfuel 450 and it makes 325/380.
I am tempted by the 383 crate motors, but the damn motor/bell housing/tranny are so tightly packed in, I thought I'd try to get by with top end work. I've had the motor in and out of the Lemans three times, but there's so much room to work with there. I'll do up the costs and see how the total project works out.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Sourcing your cam elsewhere is what I recommend.......the three flat tappet camshafts that Edelbrock has are the same three cams they had 20 years ago.....
I would go here with a 1.6 rocker on the intake and a 1.5 on the exhaust....
https://www.howardscams.com/hydrauli...cams-110041-10
With the 3.36 and I would assume an M20 4 speed......this cam will run very strong.......easy 340 to the tire with the right setup.....pair this with an Air Gap from Dart or Edelbrock, Long Tube headers and a 750hp carb.......it will love it.
There are also much better head choices out there like the Dart 180 Pro 1 and the Trick Flow DH175.....both heads have a much nicer casting in the port than Edelbrock. There is nothing wrong with the Edelbrock head....it is just not preferred to others by me.
The Trick Flow has the advantage of a 60cc combustion chamber to get close to 9.7-9.8 to 1 compression with the dished pistons. A lot of folks make a huge deal about dished pistons having no quench and that is true.....but I have put many heads on L-48's and Goodwrench 350's with zero issues and they run like a raped ape......
Jebby
I would go here with a 1.6 rocker on the intake and a 1.5 on the exhaust....
https://www.howardscams.com/hydrauli...cams-110041-10
With the 3.36 and I would assume an M20 4 speed......this cam will run very strong.......easy 340 to the tire with the right setup.....pair this with an Air Gap from Dart or Edelbrock, Long Tube headers and a 750hp carb.......it will love it.
There are also much better head choices out there like the Dart 180 Pro 1 and the Trick Flow DH175.....both heads have a much nicer casting in the port than Edelbrock. There is nothing wrong with the Edelbrock head....it is just not preferred to others by me.
The Trick Flow has the advantage of a 60cc combustion chamber to get close to 9.7-9.8 to 1 compression with the dished pistons. A lot of folks make a huge deal about dished pistons having no quench and that is true.....but I have put many heads on L-48's and Goodwrench 350's with zero issues and they run like a raped ape......
Jebby
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Instructor
Joined: Apr 2018
Posts: 165
Likes: 92
From: Buxton ME
Thanks, Jebbysan. Since my morning post I've been reading other cylinder head posts, so I'm already smarter than I was over coffee. I love the new feature on this forum that links you to similar past posts, very helpful. The attraction of the Edelbrock kit is heads, cam kit and manifold plus all the hardware for around $2K. But at $1,500 for the DH175 heads, $225 for a cam kit and another $175 for the intake, there's not much difference except hardware and gaskets.
I had an Edelbrock 500 on my Lemans and was not crazy about it. I love the Quickfuel.
Cheers
I had an Edelbrock 500 on my Lemans and was not crazy about it. I love the Quickfuel.
Cheers
Racer
Joined: Dec 2003
Posts: 487
Likes: 160
From: Two Lane Black Top
So, if I'm just shooting for 325 hp/375 tq, I might get away with the iron Vortec heads, the Edelbrock intake and something like a Lunati Voodoo cam (219/227)? I have this cam in my '64 Lemans 326 with modified heads and a Quickfuel 450 and it makes 325/380.
A roller 383/400 with at least ten more degrees on both sides will be way more fun. ~230/236
I am tempted by the 383 crate motors, but the damn motor/bell housing/tranny are so tightly packed in, I thought I'd try to get by with top end work. I've had the motor in and out of the Lemans three times, but there's so much room to work with there. I'll do up the costs and see how the total project works out.
It will make for a far more fun combo.
Less than 350-375 wheel hp (450 flywheel hp) is pretty weak these days.
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Thanks for responses. The motor has 90,000 miles on it, but surprisingly it makes 180 to 200 psi all around on a compression test. It's a 4-speed car with a fresh tranny rebuild and 3.36 gears.
So, if I'm just shooting for 325 hp/375 tq, I might get away with the iron Vortec heads, the Edelbrock intake and something like a Lunati Voodoo cam (219/227)? I have this cam in my '64 Lemans 326 with modified heads and a Quickfuel 450 and it makes 325/380.
I am tempted by the 383 crate motors, but the damn motor/bell housing/tranny are so tightly packed in, I thought I'd try to get by with top end work. I've had the motor in and out of the Lemans three times, but there's so much room to work with there. I'll do up the costs and see how the total project works out.
So, if I'm just shooting for 325 hp/375 tq, I might get away with the iron Vortec heads, the Edelbrock intake and something like a Lunati Voodoo cam (219/227)? I have this cam in my '64 Lemans 326 with modified heads and a Quickfuel 450 and it makes 325/380.
I am tempted by the 383 crate motors, but the damn motor/bell housing/tranny are so tightly packed in, I thought I'd try to get by with top end work. I've had the motor in and out of the Lemans three times, but there's so much room to work with there. I'll do up the costs and see how the total project works out.
Scotty
Thread Starter
Instructor
Joined: Apr 2018
Posts: 165
Likes: 92
From: Buxton ME
Scottyp99 - done lots of compression tests, usually get pretty consistent results. I'd be interested in other members numbers. A quick online search shows the numbers varying from 150 to 190 psig. I also have all the paperwork and receipts for this car going back to new (bought it from the son of the second owner) and don't see any record of motor work. Don't those mild 70s cams close the intake valve pretty soon leading to good dynamic compression?
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Top end kits are compromise at best. You’ll get more power, likely not as much as you’d like or where you’d like it.
Thread Starter
Instructor
Joined: Apr 2018
Posts: 165
Likes: 92
From: Buxton ME
Thanks for all the responses. The budget won't allow the crate motor this year, so I'm going to focus on getting ready for later mods. This year I'll add good long-tube headers and a 2.5" exhaust system (have to do that no matter what the motor is), swap on an Edelbrock Performer I found on Ebay and will get dizzy and Q-Jet sorted out per Lars' papers. I'll do some 0-60 runs before and after and post any results in a new thread later in the year.
Cheers
Cheers
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
Truthfully, the L48 can be upgraded successfully within limits. It is a 2 bolt main block. basic crank and rods.
Not L82 stuff. But still very capable of 350 HP.
Biggest limiting factor is the dished pistons.
Replace pistons with flat tops. use a. 015 head gasket if you are not decking the block.
Then with the Edlebrock heads, you can see some increase in power .
Rear end gearing. Huge!
If your car is an Automatic. (God help you). You will likely have a horrible ratio 3.08 -1 I think. absolutely horrible for any kind of acceleration.
Not L82 stuff. But still very capable of 350 HP.
Biggest limiting factor is the dished pistons.
Replace pistons with flat tops. use a. 015 head gasket if you are not decking the block.
Then with the Edlebrock heads, you can see some increase in power .
Rear end gearing. Huge!
If your car is an Automatic. (God help you). You will likely have a horrible ratio 3.08 -1 I think. absolutely horrible for any kind of acceleration.
Scotty