looking to buy a motor for my 72SS. Saw an ad in the paper for a 454 with L88 rods, TRW 10.7 pistons with 69 ZL1 aluminum heads (long block). how good are these heads. how can you tell if these heads are ZL1 heads. also the motor is setup for and automatic. if I want to put the motor in a 4 speed car. does the motor have to be balanced after i change the flywheel or can i just bolt on a 454 4 speed flywheel

[This message has been edited by nebula72 (edited 08-04-99).]

ZL1 heads would have have D shaped exhaust ports ( 2 nd gen GM alums). Be careful. Not many ZL1's made. High probability of BS.

Aren't 454 rods and 427 rods different? I mean L88 rods ( Which I have, they have 7/16 boron bolts with a little dimple on the head for the strech gauge you use to set them instead of a torque wrench) are for a 427. Is this motor a 427 or 454. Of it's a '27, then you DO NOT use a externally balanced flywheel. If it's a 454, I hope someone replys about the rods. I think they are different, confirming my original thesis, it's BS.

If it's a 427 with these components, I think you have a helluva good motor there. For comparison I would sell my 67 L88 with the original 67 block for $4500. ( Academic it's not for sale.)



[This message has been edited by Gene Chas (edited 08-05-99).]

IMHO, there's a lot of better heads around than the early GM aluminum. They were prone to cracking, and alot of them had pistons stuffed through the chamber and were welded back together. If they're in good shape (I'd pull them off to look in the chambers) then I'd go ahead and use them. They should be open chamber design with round exhaust ports. Casting number is 3946074. 396/375 horse with L89 for 1969 would be casting number 3919838.
The 3946074 head is also used for the '70 L78 with L89 aluminum heads. Be sure to check the date of the heads.
As far as the rods, they are the same physical size, and as long as they're balanced as a set then there's no difference. The L88 rod is, however, magnafluxed and shotpeened, and bushed for floating pistons. Like Gene said, they have the Boron rod bolts. If it is a 454 then you'll need an externally balanced flywheel for a 454.
At 10.7:1 you'll likely need to mix the gas with some good stuff to get the full potential of the combo.
Ought to be around $3500 if it's fresh and the heads are good.

Dave, thanks for the input. I assumed ( there's that word again!)that by 69 they got rid of those round exhaust ports and went with the D's. My "roundies" did indeed crack once and were expertly welded back up. Further, I've heard the same from a local BBC expert builder, new aftermarket alums are better than the early GM's.

Nebula, there you go. Dave says it's worth $3500 compare that to what the asking price is and definitely pull the heads if its not already disassembled.

Also, IMO, the crank is real key. The L88 crank is forged, Tufftrided, polished and chamfered. Make sure it's a forged crank at least. It sounds like it should be judging by the other components. My crank has a real grey look to it. Forged cranks will "ring" when you tap them with something.

If it all checks out and the price is right sounds like a good combo.

[This message has been edited by Gene Chas (edited 08-05-99).]

thank guys...the guy selling the motor wants 2700 for it. he says theres less than 10,000 miles on the motor and it has 600HP.
up until now, i was planning on having Jack Merkel racing engine build my 454 which is all apart and purchasing the Edelbrock aluminum heads. but that will cost a bit more than a complete assembled motor with the L88 heads. are the Edelbrocks better thant the L88's???
im trying to build an 11 second street car:
72 chevelle 3.73 12 bolt.
S T-10 4 speed tranny.

Performance-wise I'd like to believe that the Edelbrocks are better than the L88 heads just because of 30 years worth of development advances. On the other hand L88 heads are just plain cool...

Ideally as far as balancing goes, anytime you add a new component you should balance the rotating assembly together. 11's are tough with a real street car with "only" 10.7:1 compression as this handicap means you'll really need to tune the suspension for straight line traction and not street handling.

Nebula, that sounds like a pretty good deal . The Edels are probably a bit better than the stockers, I know tht Pro1's and square RPM's flow more. But geez, that's a good deal. I hope he's a reputable seller. I mean look if you can get a good rat for say,$2500, that's a good deal! BTW, the best negotiating tool is pictures of Ben Franklin in your hand.

11 secs is hot and a far cry from 12. My near stock 396 shows 13.60 on a Gtech ( 67 4 speed 3.73 w/ Drag Radials) and I hope to jump into the 12's with the L88. The bottle would probably give me 11's. Maybe, just maybe.

I say 2700 is a good deal. Fit your 454 external flywheel on and GO!If he's correct on the parts inside, I don't think you'd take a bath on it even if you parted it out. No way you could get away with that amount at Merkel I would suppose.

Good luck on your choice. To me, 25 pictures of Ben and I'd be racing.



[This message has been edited by Gene Chas (edited 08-05-99).]

thanks guys. im gonna take a look at the motor either tonite or friday. is there anything i should look at to see if the heads are good?

Edelbrocks are a ton better than Early GM's. Dart cast iron heads are better than both, but they add mondo weight. I would pull the heads off to verify that the pistons are indeed forged TRW's. They should have a number like L2349F on them. Any oversize will be marked. .030; .060 or STD for standard. I would think they would have about a quarter inch dome on them. When you remove the heads, look in the chambers for obvious welding repairs and/or grinding. Look in the water jacket openings to see welded areas. Also, these heads had some problems with the rocker arm stud boss breaking off. Look around the area under the guide plates for weld.
If he won't let you pull the heads, get him to write you a warranty that the heads are good.
Price sounds like a good deal. Look at the balancer on the end of the crank to see if it's got a weight on the inside of the hub. This would indicate 454 crank.
Good luck!
Dave