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So I just discovered that my supposedly original LT-1 had a lobotomy at some point when the heads were replaced with #462624 heads. Foolish me - I checked that the block was numbers matching, but didn't think to check under the original LT-1 valve covers. The rest of the car is very original (I checked the trans and rear end before purchasing it.)
So, I am guessing that the camshaft, lifters and pushrods aren't original either, since I would suppose the solid lifter setup was replaced with hydraulic lifters to accomodate the later model heads. Since I can't quite get this engine to run correctly (I was planning to check valve lash when I removed the valve covers and got my surprise) I'm wondering if they kept the original camshaft.
So, to cut my boring sob story short, I am asking fellow C3 forum members their advice on what would be the most practical replacement heads to go with on this car. I'd love to return it to original - but I am guessing that #3998916 heads are nearly impossible to find and ridiculously expensive. Reading the 4th edition NCRS judging guide that I have, I'd have to match the casting symbols on the side of the head as well as the pushrod guide plates under the oil cap. Since I doubt this will happen, I am looking for some reasonable heads and camshaft that would give me comparable performance to the original LT-1 setup. I want to keep the original aluminum intake manifold and Holley carb setup. Solid lifter is not a definite, since if the casting symbols aren't there, it won't matter if it is solid lifter or not. This is a street cruiser - while I'll occasionally jump on the throttle and wind it up, it won't be very often.
go buy one of the books with SBC builds.....they will have different combinations and have dyno tests of the set ups....its hard to argue with one of their builds with actual dyno test results
I've been reading the Hot Rod "8 Budget SBC Head Shoot Out" article. Good information there.
that's the kind of articles that I am about, you need to make sure there is no hidden agenda or plugging some advertisers wares, and if they have dyno tests you are kind of assured of knowing what you are getting
Trick flow make an aluminum head that looks like the old double hump heads,a coat of paint and few would tell the difference. Any aftermarket modern head will substantially out perform the originals. I'll definitely fall out with many on the forum they will recomended a hydraulic roller cam but we're it me I'd find a solid lifter cam matched to your heads.those LT-1 engines sounded so cool with solid lifters doing otherwise would be just wrong.
462624 were also used for service replacement 2.02 heads. But they are crack-happy. May want to check those before you make any decisions. As far as replacing them, Vortecs are only GM head worth considering, with the required manifold swap included.
Trick flow make an aluminum head that looks like the old double hump heads,a coat of paint and few would tell the difference. Any aftermarket modern head will substantially out perform the originals. I'll definitely fall out with many on the forum they will recomended a hydraulic roller cam but we're it me I'd find a solid lifter cam matched to your heads.those LT-1 engines sounded so cool with solid lifters doing otherwise would be just wrong.
Those Trick Flow DHC 175 (TFS-30210007) look mighty interesting! I need to check the pattern on the ends, but those might do the trick! (pun intended)
i looked at those Trickflow heads when i did a recent rebuild, but they weren't released yet.
so went alli, but machined the ends to appear "old school".
coat of paint and with all the brackets for the alternator, aircon, smog pump, it's hard to see the ends anyway....
Mine has 487x heads you could find a set if you wanted to search for a while
If you want a off the rack replacement old school head these are very reasonable performance iron heads with screw in studs and guide plates
Of course many here will say you have to do aluminum heads change the intake, do a roller cam, toss in a stroked crank etc etc anything less is a waste of time.
I think it depends on budget and goals and suggestions on threads like this can go all over the place and not always pertain to your personal situation.
I would probably back date it to 1970 LT-1 Specs and be done with it.
OR - 64cc heads and an aftermarket cam - cam selection would be Crane F-278-2 small solid lifter. I have it in another car now. Open/close events are close to GM LT-1 events but more lift.
do the TFS head, its new, looks the part and is 10x the head any GM one will be.
Id never buy a used head unless I had no other choice, it came from a known good machinist etc. Too much cobbled up junk that is cracked out there. The difference will be night and day, a set of headers will really compliment it.
Put a pair of Dart 180 platinums on it with Trend pushrods and Comp Roller Tip rockers in a 1.6 ratio.......if it is the stock LT-1 cam....it will pickup huge......probably to the tune of 50 horses or better......
The LT-1 intake is surprisingly good 50 years later along with the big 780 Holley.......
All of this is worthless without a premium set of headers though......
Get the 72cc heads if you are worried about pump gas.
Also.....if you follow through with this.....GET THE DISTRIBUTOR CURVED!
All in by 3000 rpm....around 16-18 initial and 34 total with the Dart chambers.
This will feel like a whole different animal when finished.
Put a pair of Dart 180 platinums on it with Trend pushrods and Comp Roller Tip rockers in a 1.6 ratio.......if it is the stock LT-1 cam....it will pickup huge......probably to the tune of 50 horses or better......
The LT-1 intake is surprisingly good 50 years later along with the big 780 Holley.......
All of this is worthless without a premium set of headers though......
Get the 72cc heads if you are worried about pump gas.
Also.....if you follow through with this.....GET THE DISTRIBUTOR CURVED!
All in by 3000 rpm....around 16-18 initial and 34 total with the Dart chambers.
This will feel like a whole different animal when finished.
Jebby
Yeah, I had Lars rebuild my distributor and he curved it for the stock LT-1 setup. I'm all in 36 at 3000 rpm. so at least I'm set there. Next step is to see if the cam is original, and I need to pull a pushrod and look down there with some type of camera probe to see of the lifters are solid or if they were replaced as well. My guess is they were replaced.
i know people love solid roller set ups, but they are more maintenance. If you're just cruising it makes more sense to have hydraulic lifter.
I think you need to make up your mind; do you want to stay stock as possible, or not? If not, you can get crazy with the options in the aftermarket and get way more power.
If it's not the original cam:
I don't know if you've installed a flat tappet cam before (I'll be honest, I haven't), but there is some risk of installing one and having the break in procedure not go well, and trash the motor. In a Hot Rod article they talk about how they even trashed a motor during cam break in on one of their builds. If you have a matching numbers engine, this risk may not be worth it.
If it were me, and the cam isn't original, you're set on replacing it, and you have money to spend, it makes most sense to go to a hydraulic roller.
If you do want to stay original, spend the money and get the original heads, although this will likely cost you more money after any clean up/ machine shop work is done.
So, thanks to Joe79Vette, I acquired a really nice set of 487x heads which I promptly sent to Indy Cylinder Head for a redo. They rebuilt them with the larger 1.60/2.02 valves and springs for the original cam profile. Also had the guide plates installed. This winter, I plan to tear the motor down and check to see if it still has the original cam. If not, I'll go with a similar profile new cam, solid lifters and hardened pushrods.
Good move on the solid lifter cam, nothing like em. With new polylocks you wont be adjusting them "all the time" like you hear, they are plenty reliable.
Plus that sound....an LT1 car with a hyd cam can be heard right away kind of a turn off.
06-03-2018, 04:47 PM
New heads for '72 LT-1..any recommendations?
Foolish me - I checked that the block was numbers matching, but didn't think to check under the original LT-1 valve covers. The rest of the car is very original (I checked the trans and rear end before purchasing it.) 
