487X vs. 487 vs 993 SBC Cylinder Heads
 

My brother and I are looking at potentially building a SBC 350/270 combo engine and have some questions for the engine/cylinder head experts.

1) Is the 487X cylinder head allowed for stock eliminator?
2) What is the difference between the 487X and the 487 cylinder heads?
3) Is the 993 cylinder head comparible to the 487X and the 487?
4) Which cylinder head is the best to use for the 350/270 combo or are they all pretty close in performance.
5) How much horspower and torque could I reasonably expect from the 350/270 combination.

Sorry for the long list of questions but, there is a laundry list of opinions from non-class racers on the internet and I don't know who or what to believe. I figure there are guys on class racer that are familiar with the 350/270 combo and will have better information.

Thanks
Nelson Kowal

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

Nelson, if you do a search on here for any of those heads you will find some posts that might answer some of your questions. Some have had good luck with the 993.
I was told by a Division 1 tech official that the 487x is accepted in place of the 487.
Also, check the for sale section...there was a bunch of 350/270 stuff for sale. http://classracer.com/classforum/showthread.php?t=56482
Good luck.

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

John you have a PM

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

The flow bench doesn't tell the whole story,but is pretty good start, myself I have checked 882,624 for 350's 450,416 for 305's 743 for 4.3 and by flow numbers are almost identical.
.450'' lift is highest lift went to these were junkyard heads cleaned and checked,we checked a dozen or more 882, have checked close to that many 450,416 ,have only checked a couple 624 and 4.3 heads.
165-175cfm @25'' around .400 lift
Mike Taylor 3601

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

Call me I have lots of parts for that combo
And have done lots of testing. 218-391-8559

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

1 those heads are all good and very similar
In both flow and hp.
2 the 487x is allowed but there is more of
A difference between good castings and
Bad castings than there is from one casting
Number to another.
3 horsepower can vary greatly from one
To another but 410- 430 depending on the
Dyno will get you down the track very well.
I have heard of some making more but the
Best dyno is 1320 ft long and it does not matter
What the dyno sheet said it made its the
Et ticket that does! Hope that answered your
Questions.

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

AMEN to the 1320 dyno Ron. We have three different Olds engines for our SS/NA Cutlass, all very different combinations. NONE of the engines have been on a real dyno, and I think most would say our car runs OK.

Jerry

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

If 487X, 487, & 993 share similar air flow capacity, in your opinion which casting is the best choice regarding casting integrity (robustness), resistance to cracks, core shift, etc. is the best of the bunch?

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

Flip a coin.

Re: 487X vs. 487 vs 993 SBC Cylinder Heads
 

I've run all three on my Nova.If each set was done exactly alike I don't think there is a hoot of difference in any of them.The book say's the 487 has more intake port volume but the best I have run was with the 993's.Hope this helps.