need info on "998" SBC heads - The 1947 - Present Chevrolet & GMC Truck Message Board Network

nu2-72 · 05-30-2002, 04:15 PM

Anyone have information on heads with the last three numbers "998"? I am familiar with the "441, 882's" and a few others. These I know nothing about. Belong to a friend. Thanks

*Fast68Chevy* · 05-30-2002, 04:21 PM

you mean 993 ? 993 are 350 heads, most have little valves, and are truck only heads in the early 70's, up, are heavy cast, no cracking problems, and are pretty common, great candidates for planing/milling and installing large valves and porting out and polishing up

**1970 CST Short Wide** · 05-30-2002, 04:21 PM

Whats the whole # and have you looked at mortec.com ?

**1970 CST Short Wide** · 05-30-2002, 04:23 PM

Fast could be right double check that # the 8 could be a 3. easy to misread

nu2-72 · 05-30-2002, 07:01 PM

Thanks everyone. Fast, I don't know what they say on them. He is relaying the message to me and this is all I know. I will have him check again and then check Mortec. Thanks.

70shortnphat · 05-30-2002, 09:34 PM

The bad part about having all that machine work done is by the time its all over with youve spent enough money on them you could have just bought new ones from World ready to go!It just seams that machine work has gotten so expensive and the price of good aftermarket heads have come down.

*Fast68Chevy* · 05-30-2002, 09:55 PM

yeap yeap, you can get some iron eagles for 750 now.

texnician01 · 05-31-2002, 12:04 PM

I would be willing to bet that they are 993 and not 998 cause I made that same mistake on my set. make sure you check the valve sizes. a lot of the 993 heads came out with 1.94 intake and 1.50 exhaust valves. they are a heavy casting head and are one of the best for street performance on a 350. these were the heads that were used on all of the target master replacement engines. the ones on the target masters were made in mexico and have HENCHO EN MEXICO cast into them. the 1.94/1.50 valves will give you excellent street performance and low end torque. if you want to run high RPM's all of the time I might look for a set with 2.02 valves but if you overheat them they are prone to crack.

05-30-2002, 04:15 PM	#1
nu2-72 Senior Member Join Date: Apr 2001 Location: Amazonia, Mo. USA Posts: 2,821	need info on "998" SBC heads Anyone have information on heads with the last three numbers "998"? I am familiar with the "441, 882's" and a few others. These I know nothing about. Belong to a friend. Thanks __________________ 72 3/4 4x4 350 4spd 72 3/4 4x4 350 auto 2004 Duramax Silverado 4x4 2006 Duramax Crew cab 4x4 2010 Harley Ultra Limited 2011 Harley Street Glide

05-30-2002, 04:21 PM	#2
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	you mean 993 ? 993 are 350 heads, most have little valves, and are truck only heads in the early 70's, up, are heavy cast, no cracking problems, and are pretty common, great candidates for planing/milling and installing large valves and porting out and polishing up Last edited by Fast68Chevy; 05-30-2002 at 04:24 PM.

05-30-2002, 04:21 PM	#3
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,185	Whats the whole # and have you looked at mortec.com ? __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2019 GMC Diesil Dually. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

05-30-2002, 04:23 PM	#4
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,185	Fast could be right double check that # the 8 could be a 3. easy to misread __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2019 GMC Diesil Dually. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

05-30-2002, 07:01 PM	#5
nu2-72 Senior Member Join Date: Apr 2001 Location: Amazonia, Mo. USA Posts: 2,821	Thanks everyone. Fast, I don't know what they say on them. He is relaying the message to me and this is all I know. I will have him check again and then check Mortec. Thanks. __________________ 72 3/4 4x4 350 4spd 72 3/4 4x4 350 auto 2004 Duramax Silverado 4x4 2006 Duramax Crew cab 4x4 2010 Harley Ultra Limited 2011 Harley Street Glide

05-30-2002, 09:34 PM	#6
70shortnphat "See the U.S.A....." Join Date: Apr 2002 Location: Richmond TX. Posts: 269	The bad part about having all that machine work done is by the time its all over with youve spent enough money on them you could have just bought new ones from World ready to go!It just seams that machine work has gotten so expensive and the price of good aftermarket heads have come down. __________________ 1970 short bed fleetside 1949 all origional chevy 3600 1974 camaro Richmond , Texas(just S.W.of Houston)

05-30-2002, 09:55 PM	#7
Fast68Chevy Account Suspended Join Date: May 2000 Location: IL Posts: 0	yeap yeap, you can get some iron eagles for 750 now.

05-31-2002, 12:04 PM	#8
texnician01 Senior Member Join Date: Mar 2002 Location: 12 Miles South of Des Moines, Iowa Posts: 359	I would be willing to bet that they are 993 and not 998 cause I made that same mistake on my set. make sure you check the valve sizes. a lot of the 993 heads came out with 1.94 intake and 1.50 exhaust valves. they are a heavy casting head and are one of the best for street performance on a 350. these were the heads that were used on all of the target master replacement engines. the ones on the target masters were made in mexico and have HENCHO EN MEXICO cast into them. the 1.94/1.50 valves will give you excellent street performance and low end torque. if you want to run high RPM's all of the time I might look for a set with 2.02 valves but if you overheat them they are prone to crack. __________________ 69 C-10, 340HP 327 55 chevy 4 door 150 47 Willys CJ-2A 05 Harley Night Train 06 1200 Sportster (Wife's bike) 70 Honda CL350 OIF2 & OIF7 Veteran Nathan & Tiffany

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