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Hello. My 80 L48 needs a top-end rebuild and it has the 462624 cylinder heads. These have 76cc chambers and are crack prone. I am a fan of originality, but I just don't think its worth the effort to rebuild.
This leaves me with the question of what I should replace them with? My only requirement is I need the accessories to bolt back up to the same places. The goal with this vehicle is not speed/power, so I don't need anything wild.
Thanks.
Hello. My 80 L48 needs a top-end rebuild and it has the 462624 cylinder heads. These have 76cc chambers and are crack prone. I am a fan of originality, but I just don't think its worth the effort to rebuild.
This leaves me with the question of what I should replace them with? My only requirement is I need the accessories to bolt back up to the same places. The goal with this vehicle is not speed/power, so I don't need anything wild.
Thanks.
How about a complete top end kit, cam, heads, and intake? Look at Summit Racing and Jegs.
I had the same set up as you in my 1980 L48. But did a complete top end upgrade and am pretty happy with set up. Before you even decide to replace your heads, how much mileage is on your car? How is your compression right now? My car had under 41,000 original miles and was smoking a little do to I believe dried out valve guides. The car was parked all the time. It would throw a little smoke as soon as you started it. I had the cam upgraded to a roller cam and the heads to 64cc heads, 2101 performer intake, 1.6 roller rockers. She sounds sweet! Very intimidating sound. She is not a fast car since she has the 3.08 rear end, but she draws attention when you show up to the car shows and that is that she still needs a good paint job. She is about an 6.5-7 right now. Work in progress.
@Jebbysan and others have posted head suggestions all over this Forum.
The big question is, are you doing this over the side of the car, or are you pulling the engine to refresh it? If the latter, you may find (like I did) that a complete, running, 5.3L LM7 costs the same as a set of aftermarket heads. Or you could find aftermarket heads and paint the engine to look completely original.
This thread starts with a head and cam swap without pulling the engine:
Ok I found some Blueprint aluminum heads that I'm going to pick up. They are complete without rockers. It uses a 3/8 stud like my current heads do. I should be able to reuse all the stamped rockers correct? I don't think I can fit roller rockers under my valve covers.
I wasn't planning on doing performance upgrades to this car. Changing the cylinder heads out is only because I don't think its worth putting money into the old ones. One day I might put a cam in it, but for now, it will remain the same.
Sure you can use the stamped rockers. Millions of people do on aluminum heads.
However, your pushrods will likely be around 0.100 short w/ aluminum heads.
You need to order a pushrod length checker ASAP.
Another option with low valve covers is Roller Tip stamped rockers. You might even find some used ones on EBay.
I did. Set of used Comp Cams for half the cost. Then I purchased new rocker ***** & nuts.
If you are not after performance have the stock heads freshened up and valve guides cut for the new style valve seals , just did this with my 80 L82 when I freshened up the motor a few weeks ago and turned out great
If you are not after performance have the stock heads freshened up and valve guides cut for the new style valve seals , just did this with my 80 L82 when I freshened up the motor a few weeks ago and turned out great
That's solid advice if you start with L82 heads and can get that work done for really cheap.
OP has L48 heads. They are best used to slightly raise the level of a lake.
I think these aluminum heads will work out. I'm going to swap the springs out for ones with less seat pressure. The current ones are for high rpm high lift, which the engine will never see.
Your 185psi cylinder pressure sounds remarkably high for a stock L48 with 76cc heads.
That aside if you are buying roller tipped rockers go with a 1.6 rocker. Free hp and you are buying them anyway so take advantage of the increased lift on a better flowing head.
That's solid advice if you start with L82 heads and can get that work done for really cheap.
OP has L48 heads. They are best used to slightly raise the level of a lake.
I'm with you there and that's why I said if " you are not after performance redo the stockers " , my L82 heads were from my black 1980 were all ready full ported by the previous owner that I had freshened up with the new style valve seals for my low mile white 1980 L82 to keep original after a engine freshen since I went with aluminum on my black 80 L82 they were just laying there in the back building waiting for use
I am about to pull the original heads off. Here is a picture:
I've noticed that the valve springs have yellow paint marks on them and the head bolts have stars on them. Is this factory or has someone been in here before?
When I eventually swap my heads I will probably go with these. I think they have all the accessory bolt holes and work with stock intake/exhaust but I didnt get a chance to call them yet to confirm. Bit pricey but they're complete. https://www.edelbrock.com/performer-...pet-60909.html
11-11-2023, 03:42 PM
Cylinder Head Information and Recommendation
