68 Yenco clone

[original owner]

Wayne, close but not accurate.This is from chevrolet, ZLX, 12.25 comp. L 88, ZL1, hybred.Iron block, alum. heads. In house use only, not sold. motion no thing to do with this motor.produced from late 60's to around late' 90's(chev alittle hazy about end date) only used for experimental purpose. end of the line for hi perf. 427's. most H.P. of all but unreliable. From chevrolet, also l-36 , desighed as a big block of medium H.P. for the use in the heavy sedan;s coupes they planed to build, and also as a motor for med. duty trucks, because of the broad torque band. Used to work for chev. back in the 70's, 80's. had chev monte carlo demo's 454, 345 H.P. chevy also used med H.P. 427,454. motors in there own brand of motor homes, in the 70's. remember those? Those were the days my friend , we though they would never end but. Thanks Bob krueger

[SuperNovaSS]

Bob,

I think your info may be a bit incorrect. the ZLX was installed in Motion cars. It was also availble to all buyers over the counter.

I also believe all 68 Yenkos started as L78s. 67s were available as 390HP.

There are many sharp cookies on this board. Try to back up your statements with facts.


Jason

[SuperNovaSS]

chris,


The 858 Heads are 66 and the 291 heads are late 69-70. Although both are closed chamber rectangular port heads, you will need 840 castings to be correct for a 68.

Jason

[RPO LS7]

[original owner]

My info came straight from chevrolet, the complete motor was never put on the market unless the history depart. has slipped a gear? Never heard of a car with that equipt, back in the day? chev stated that research was done on types of that motor till the 90's. the add could be what the industry called a teaser, to test the market for aproduct.AS 1970 was the last year for the high H.P. motors. as the ad reads that motor would have way over 700 H.P. Any info about a real ZXL car? Thanks Bob krueger. motion was the seller, not the producer in the ad.

[auschris001]

Pete,

Can we agree that there were 70 Yenko Camaro's built in 1968 and that all were 4 speed.Most were SS and at least one of the first COPO's was an SS/RS L78 (396-375hp)
That said,I am hearing that of those 70, 64 were COPO 9737 but in the initial months of 1968 6 were transplants with a COPO option
Can someone confirm this bit.

Cheers: Chris H

[auschris001]

Jason,
Dagnabbit, (see im learned texas cussin allready) I saw another matching head at a swap meet last month I will have to pay closer attention now I know what I have and am looking for.
Thanks for sorting that one out

Cheers: Chris H

[auschris001]

Jason,
Any luck on turning up a correct block # for me to look for
1968 427

Cheers, Chris H

Uhm Bob...

I'll stick to my answer on both the ZLX and the Medium Duty Truck engines.

Wayne

[sYc]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: original owner</div><div class="ubbcode-body"> Gentlemen the camaros sold in 67 and 69 with the auto tran's, had hydro, lifters, There H,P. ratings were 1967 410 H.P. 1969 425 H.P. There are no hydro. lifters on L72 427 V8's. In 1968 all camaros were m21 4 speeds, with L72 427's The L36 was producted according to G.M. from 1966 to 1969. G. M. futher states that the L36 was ment for large pass. cars,, med. trucks, but also found it's way into corvettes, plus the large body bel air, Impala car's in the late 60's.the same motor with 3x2 barrels in a vette was rated at 400 H.P.With a diff. L number.I had one in 69 an L36. As to 67's,most had the blocks changed at dealer(yenko) except auto trans cars.Factory built that way,the tranny's of the day had a very hard time in auto form handling the H.P. of the L72. All 68's had 4 speed m21's,L72's(as all the three year's should have had, no auto's) <span style="color: #FF6666">I am not for sure why you feel all Yenkos should have been 4 speeds, as beginning in '68 GM had a very good auto trans, that could handle the solid lifter 427 quite well, even when modified. I know of several such beasts that will give a 4speed a run for their money. </span> And the majority of 68,s had the L72,s FACTORY installed and all 69's.This comes from several people who I talked when I worked for chev. in the mid 70's,who worked on this project for chev. yenko over rated the H.P. in the 68 camaro's from 425 to 450 also the 69's, the same. the auto trans camaros were also over rated. 67 from 390H.P.to 410, 69 from factory rating 390 to 425 yenko H.P.? <span style="color: #FF6666"> '69 auto was 390 HP...You are joking..right?</span> The 68 4speed camaros, L72 factory 425, yenko 450H.P.But in his defense he did modify them some. never heard of a L-88 yenko camaro, but thats just the ones I saw shipped to minnesota. Question of the day whats a ZLX 427 chev v8. thank you Bob krueger. </div></div>