[stealthy1991]

Looking to buy these heads but googled them and found out the intake ports are different. Here's more info..
Specs:
190cc Intake Runners, 64cc Chambers, 1 piece stainless valves; 2.02 Intake valves, 1.60 exhaust valves. Flow about 260/180 CFM.
The valve springs have a max lift of .600, open pressure is 325 lbs, closed pressure is 130 lbs.
Straight Plug. 3/8 studs, 5/16 guideplates. Standard accessory bolt holes.
Accepts center bolt valve covers and perimeter bolt valve covers. Accepts vortec intake manifold and Standard small block chevy intake manifold.

they were machined to fit the larger valve springs. They were also machined by the pushrod area so you can run a higher lift cam without worry of your pushrods rubbing the heads. I think about .550 lift.

these heads have been machined to fit a standard intake and valve covers. These studs are screw in type. These are GM castings that have been ported and polished. The casting number is 16485906. Thanks.

[bondo]

Ayuh,.... Expect the same answers ya got in this thread, askin' the same question...

[CJ_1080]

Those are 906 vortec castings. Off 3/4 or 1 ton trucks. They are just modified.

[stealthy1991]

Thanks CJ. Just wanted to know before I spent the money.
On anothe forum some guy said the ports are bigger than the regular vortec heads. Will these work ok with a Summit SUM-226018 intake?

[cool rockin daddy]

Too funny, Bondo, too funny. Just another example of what rodding is coming to these days......people afraid to do anything to their rides without polling a thousand people and then being to afraid to believe the poll answers. No individuality anymore in the hobby.

[stealthy1991]

Thought that's what forums were for. This question was actually different from the first one. I decided to go with a made for vortec manifold because of some help I got here. I did find some helpful people on this forum. I'm sorry I don't know alot about SBCs' like you guys do. I've been a Mopar guy all my life. Working on this car for my wife. Maybe I'll just stick to mopars. So do you guys just sit around waiting for somebody to post so you can make sarcastic remarks?

[Greg T]

Originally Posted by stealthy1991

Thought that's what forums were for. This question was actually different from the first one. I decided to go with a made for vortec manifold because of some help I got here. I did find some helpful people on this forum. I'm sorry I don't know alot about SBCs' like you guys do. I've been a Mopar guy all my life. Working on this car for my wife. Maybe I'll just stick to mopars. So do you guys just sit around waiting for somebody to post so you can make sarcastic remarks?

Not all...just one.

[cucumber1949]

Originally Posted by stealthy1991

So do you guys just sit around waiting for somebody to post so you can make sarcastic remarks?

Yeah, there are a few here who feel they must point out inadequacies LOL. Reminds me a little of the H.A.M.B. when I see it here. Just keep asking your questions and avoid the white noise, you'll get some useful information. The majority of members here are more than helpful.

[stealthy1991]

Thanks guys, I'm thinking I'll go with the with the slightly modified version Vortec with screw in studs instead of buying some high performance head aftermaket. I have a late 80s 4 bolt main block and want to get about 375 horse out of it but need a formula to do it. Putting it in a 73 Corvette with a 4speed and 3:73 gears. Would like to go roller cam but this block is originally flat tappet. I want to go with the Summit SUM-226018 intake because of hood clearanc problems I've been hearin about. It is about .400 lower than the Edelbrock performer. I think I can get away with it if I put an early C3 big block drop base air cleaner on it with a 2"x14" air filter.

[cobalt327]

Originally Posted by stealthy1991

On anothe forum some guy said the ports are bigger than the regular vortec heads. Will these work ok with a Summit SUM-226018 intake?

Unless the ports were ported, they are Vortec head ports- this means the ports are taller than a production head like a 882, etc. That's why using a standard (non Vortec) intake manifold will be a problem unless it has a LOT of material that can be ported to match the Vortec head- like a Victor or similar.

The SUM-226018 intake is like an Edelbrock Vortec Performer intake. The Summit intake says good to 6000 RPM, I think the Edelbrock says 5500 RPM but don't quote me on that. In any event, it will work just dandy w/the 906's. It will get you the HP you want, but an RPM Vortec intake would be a better choice if it would fit under your 'Vette hood.

[stealthy1991]

Thanks Cobalt, I wish I could go with the edelbrock because everything I've head is that it is the best one for the job. I may even be pushing it with the Summit intake as far as hood clearance goes. I was thinking of going with a mercruiser marine cast iron Vortec intake but I think the performance would suffer even more.

[cobalt327]

Originally Posted by stealthy1991

Thanks Cobalt, I wish I could go with the edelbrock because everything I've head is that it is the best one for the job. I may even be pushing it with the Summit intake as far as hood clearance goes. I was thinking of going with a mercruiser marine cast iron Vortec intake but I think the performance would suffer even more.

'Vette guys use the drop base air filter housings to gain some hood clearance. You might check into that if you find things too close.

POST ON DROP BASE:
What is the best way to get air flow to the carberutor?

Eckler’s for a drop-base L-88 base- HERE.

I wouldn't use the cast iron Q-jet intake. It's heavy, would cost as much or more than the aluminum intake and nothing to be gained flow-wise, either.

[cool rockin daddy]

"Thought that's what forums were for. This question was actually different from the first one. I decided to go with a made for vortec manifold because of some help I got here. I did find some helpful people on this forum. I'm sorry I don't know alot about SBCs' like you guys do. I've been a Mopar guy all my life. Working on this car for my wife. Maybe I'll just stick to mopars. So do you guys just sit around waiting for somebody to post so you can make sarcastic remarks?"

Sure buddy, that's what forums are for. But why ask the question if you ain't going to believe the answers you get? Like it was pointed out by another guy, you got the same answers in two seperate things threads you asked the same thing in.

[stealthy1991]

I just want to be sure I'm buying the right parts the first time. I don't have a big budget. Also don't want to put the engine together and find out I don't have the right combo.

[cool rockin daddy]

Ahhhh, but stealthy, that is part of the joy of rodding. Nobody knows for sure which combo is best. What might be garbage to you is treassure to me and vice-versa. 906 Vortec heads have been around for almost 20 years now and written up millions of times. You can't go wrong with them. Trust your instincts, my man.