New here, swapping vortec into 86 ss

Status
Not open for further replies.

Yav8

Master Mechanic
Aug 19, 2014
275
114
43
Manitowoc wis.
Interesting conflicting info on these heads. Looks like a L98 chamber 1.84" intake valve and similar ports to the 350 Vortec heads. It is rated at 230 hp so I would bet the above info is right.
You are right on the valve size being smaller on the 305 and on these heads the intake port has the ramp so it is good for a low rpm motor and makes more torque. The 350 heads 062 and 906s have the bigger valves and no ramp in the intake ports. The 305 will work great and with the roller cam it will make more power and its easy on parts.
 

pontiacgp

blank
Mar 31, 2006
29,270
20,391
113
Kitchener, Ontario
I don't understand why you are not putting in a 350 vortec engine, the prices I have seen on the 350 version are affordable and probably the same as the 305 which was only used on one truck and only in 96
 

Mrchillwill

Not-quite-so-new-guy
Jan 25, 2019
10
2
3
I don't understand why you are not putting in a 350 vortec engine, the prices I have seen on the 350 version are affordable and probably the same as the 305 which was only used on one truck and only in 96
I don't understand why you are not putting in a 350 vortec engine, the prices I have seen on the 350 version are affordable and probably the same as the 305 which was only used on one truck and only in 96

I got the engine for free, thats why i didnt go with the 350
 
Last edited:
  • Like
Reactions: 1 users
Oct 14, 2008
8,806
7,746
113
Melville,Saskatchewan
He has the highest rated 305 built. If in good shape with headers and dual exhaust should be 250 hp, not bad. Has anyone actually seen a pair of these heads off the motor? They may actually have even 1.94 valves, again conflicting. One guy on a forum actually sounded like he has had a set in hands. He said the ramp and ports was similar to the 350 heads, assuming slightly smaller, 1.84 intake and a 58cc L98 style chamber going on his 350. I found these on Ebay, I wish they had a close up of the ports. http://rover.ebay.com/rover/1/706-5...2&toolid=10001&campid=&icep_item=152105034002 Weird it was 96 only for the 305, are you sure? I know a guy who had a 2wd 1/2 ton with 305 Vortec and he said 28 mpg on the highway and good power, guys get that mileage with the new trucks.
 
  • Like
Reactions: 1 users

Turbo Zach

Comic Book Super Hero
Sep 8, 2015
2,534
5,874
113
50130
Back when... My girlfriend had a 96 Chevy pickup with a 305 Vortec. That thing would pull loaded horse trailers good, get up and go, got decent mileage, and would wip the older nonvortec 350 engines. I think it will make a good cruiser engine.
 
  • Like
Reactions: 3 users

Yav8

Master Mechanic
Aug 19, 2014
275
114
43
Manitowoc wis.
I have done truck heads and marine heads from the 305. Also because of the smaller bore of the 305 the 1.84 intake valve was the larges that could be used. Same size valves as the ones used in the 305 SS heads used in the monties. The 416 and the 601 were the 58cc chamberd heads with the 1.84 and 1.5 ex valves. The true vortec heads will have 4 bolts per side on the intake 1996-2001 earler heads will have the usual 6 bolts per side 1986-1995. The 305 vortec will have a square half block on the front of the heads and should be a 061 casting. Should be easy to see. The 350 vortec will have one hump for the 906 and 3 jaged points for the 062.
 

Mrchillwill

Not-quite-so-new-guy
Jan 25, 2019
10
2
3
Back when... My girlfriend had a 96 Chevy pickup with a 305
I have done truck heads and marine heads from the 305. Also because of the smaller bore of the 305 the 1.84 intake valve was the larges that could be used. Same size valves as the ones used in the 305 SS heads used in the monties. The 416 and the 601 were the 58cc chamberd heads with the 1.84 and 1.5 ex valves. The true vortec heads will have 4 bolts per side on the intake 1996-2001 earler heads will have the usual 6 bolts per side 1986-1995. The 305 vortec will have a square half block on the front of the heads and should be a 061 casting. Should be easy to see. The 350 vortec will have one hump for the 906 and 3 jaged points for the 062.
My 305 vortec has four bolts, 2 in each corner.
 
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor