Head Question

[Doug Jacobson]

I'm converting the '82 Turbo Regal motor in my S-10 Blazer over to an '85 setup. I have the motor tore down right now for a freshen ('87 pistons and cam, bearings and stuff) and was wondering about the heads they are casting number 25506293 I was wanting to know the difference if any between these and the 8445's on the later cars. Any input will be appreciated.

Thanks, Doug J.

 

[J Banning]

I didn't know it at the time, but I ran a set of 293's on my car last season. Went 11.70's with them. I couldn't see (visually) any differences between them and a set of 8445's I had. I'd like to port them and maybe use them on another motor I have Hopefully some other guys will chime in here.

-Banning.

 

[REEDOG]

I bought a set of these a while back and ran them on my car for about a year. I know that the accessory bolt holes at each end of the head are standard on the 293s and metric on the 8445s. They may be close but should be rethreaded with a metric tap before running the bolts in. The tap will remove very little material meaning the difference between the two sizes is minimal. I also recall the exhaust port shape is slightly different. 293s have a more rounded port roof, so be sure to check that the header matches. The coolant passage on each end of the deck is not bridged like the 8445 but that won't cause any problems. They will work fine.

 

[KendallF]

Originally posted by REEDOG
The coolant passage on each end of the deck is not bridged like the 8445 but that won't cause any problems. They will work fine.

Some are, some aren't. I have had a couple of sets of the 6293s, including one set that had the 6293 casting # on the bottom of the head and the 8445 casting # on the top! That set had the bridged coolant passages just like the 8445. I put them side by side on a bench with the 8445s and couldn't tell any difference.

 

[J Banning]

Originally posted by REEDOG
...The coolant passage on each end of the deck is not bridged like the 8445 but that won't cause any problems. They will work fine.

Actually now that I think about it, one of my 293's had a bridged passage on either end of the head and the other one didn't!

-Banning.

 

[Doug Jacobson]

OK then it looks like I'll give them a valve job, clean up the bowls and slap them on!!! Thanks for the info fellas.