Just wondering if anyone has done basic porting work to a pair of L98 heads (nothing fancy, just proven stuff the first time porter can do in the garage based on the photos and research posted here on TG.O), and had "before and after" dyno or 1/4 mile runs to demonstrage any real world gains?

My valve guides & seals are worn (mild puff of blue on startup), and after thoroughly researching all the options, I am considering just picking up a set of 083's used for cheap, taking them down to the bare casting, do the basic porting work over a period of time, then take them to a shop for a good valve job and guide work and final assembly, maybe some good undercut valves, and bolt 'em.

 

bump

 

I just finished porting my 083 L98 heads and they flow very well. I haven't got the car back together and it is snowing now so track times are a little way off, but I can give you peak flow #S.
They flow 248cfm@.480" lift and 185cfm@.550. This is with a bunch of porting and bigger valves (2.02-1.60). I will let you know how it runs once it is ALIVE

 

look up rhuarc31...hes got the most informative peice on porting L98 heads you will ever find...no ****...he ported the **** out of them (at home) installed bigger valves and they flowed about what the 190 arf's flow...around 265 cfm
there are 4 parts...theres number 1..2 and 3 are linked together, then theres 4

 

I have been running low 8.7s in the 8th in the high 70s mph. This equates to 13.6s in the qtr based on the 1.56*8th time method.
I am porting some 083 heads right now. Last stage they were at 200 intake and 170 exhaust on this particular flowbench. Started out at ~185/106 if I remember correctly. My dad just did some unshrouding to my chambers, and I'm going to do a little more to the intake port before retesting, and installing...with stock cam and 1.6 roller rockers and new springs, valves, etc. Probably early January on that.

In the meantime, I just took off my stock 083 heads, did a quick bowl blend job, a tad of intake port gasket match (very minimal)...and put them back on. Only new valve seals other change. Car feels more dangerous now is all I can say at this time. Tires spin way too much. If the weather stays dry tomorrow, I will have a time to report. Hopefully, it will be a new best. May have to give up the GT+4s and get some real rubber.
Also planning to test my Hypertech chip versus my stock chip for my mods at this stage. Haven't gotten into prom burning yet...that's one of the next steps.



Edit:
I also removed some welding on the inside openings of my 1-5/8" SLP headers...as well as cut open the SLP header gaskets a bit where they were blocking my exhaust port of the head.

Stock block, cam, converter, gears...

 

Before:
8.72 sec @78.96 mph 8th mile
1.975 60'

After mild bowl blending and a TAD of intake gasket matching, plus some carbon buildup removal...ONLY
8.60 sec @80.20mph 8th mile
1.937 60'

The car actually did not feel faster. Upon recollection, I shifted into 3rd a bit earlier than usual...Picked up a bit throughout the run, 60' to finish.

Got in 8 runs. 1st one was time above. The other 7, I spun out on my Goodyear GT+4 tires and stock suspension save for SFCs.

The heads were a restriction obviously. The little I did freed up quite a bit. On this Stock Camshaft.

Besides tires, not sure what I want to do next to this car. I do have my 083 heads that I have more porting on, and the 1.6 rockers...as well as some stock ZZ4/L98 heads I can play with, too.

 

Is your base fully ported?

 

Accel base untouched
Plenum ported, non-siamezed
Accel runners, siamezed 1 inch in on plenum side

 

New Nitto 555R tires @ 19 psi.
New times in sig.

People quick to chunk their stock cams, and heads shouldn't be so hasty. Obviously, more is left in this combo...simple one at that.

 

I have dyno numbers for mine now. See my sig. I have a hotcam, headers, and 2.02/1.6 valves too.
Later,
Charlie

 

I know this post is super old, I ported my 083's a while back. gasket matched, some bowl work and clean-up of the casting, nothing fancy.
218cfm @.500" lift on intake and 173cfm @.500 lift, my flow was tested by the late Joe Sherman of Joe Sherman racing

 

My Dad done some work on mine as well. Said he is sure it would help some on the exhaust side. I never got to see them before he bolted them on but he said he spent a whole day on them and was sure it had done some good. He has had a lot of experience with Camel humps and said the 083s were very similar. I don't know how much over stock it helped but I can tell you the car pulls way better than I thought it would especially running on TBI. Car will pull strong to 5300rpms and Ive already outran a C3,C4, and newer tuned Diesel pickup just out playing around but no track times yet.