miss match ports
- Thread starter denny
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Thanks for the link, Mike. The consensus on the link is basically those heads are Chinese junk. Good flow at high lifts after porting (.700) at the expensive of flow at .300 to 500, which is not really what you want with a .550 max lift street cam.
Looking at the flow numbers for the bigger valve heads, an untouched set of Vortec heads from the junkyard will out flow the small valve head with a "300 Hp" hydraulic street cam and the headers won't leak horribly where there is only 1/8" of metal for gasket seal when you use rectangle port headers.
Looking at the flow numbers for the bigger valve heads, an untouched set of Vortec heads from the junkyard will out flow the small valve head with a "300 Hp" hydraulic street cam and the headers won't leak horribly where there is only 1/8" of metal for gasket seal when you use rectangle port headers.
You know Denny, I hope this works out for you too and the hobby keeps you busy in your retirement. Forum conversations come off different than face to face conversations some times. I'm sure I'm not the only one who sensed the tone building about what you have there and wish to use.....I feel you explained your position well. Use what you have, it's your build.
I think it's pretty shitty that you're probably sorry you even bothered asking......and then get accused of "giving us sh*t" and being told what you have is "Chinese junk"? -although perhaps that is not referring to your heads specifically.
I'm sure you have a budget rather than a garage full of parts to put this together with, Me too-so I hope that combo gets you to where you want to be. I also hope you continue to ask questions and post up your progress, good and bad. It may not help everyone, but it will help some.
I think it's pretty shitty that you're probably sorry you even bothered asking......and then get accused of "giving us sh*t" and being told what you have is "Chinese junk"? -although perhaps that is not referring to your heads specifically.
I'm sure you have a budget rather than a garage full of parts to put this together with, Me too-so I hope that combo gets you to where you want to be. I also hope you continue to ask questions and post up your progress, good and bad. It may not help everyone, but it will help some.
You'll get the engine worked out but you got the hard part done, that car looks great
Low lift numbers and port velocity are the key goals here in a street engine. Compression is probably #3 on the list. According to the Amazon pictures it looks like the ProComp heads are double drilled for Vortec style intakes - which is interesting.
I only recommend what I recommend based upon my experiences. Which include building a low-compression junkyard 355 with Vortec heads and 1-5/8" mismatched headers that ran mid-12s @ 110mph; all used, found and/or scrap bin parts.
I would feel it a shame to condone the use of a sub-200 dollar cylinder head with the characteristics of the ProComp head. Maybe they need a healthy PD blower to shine?
Denny, please prove us wrong.
thanks for the reply SSpev. cam specs are Crower part number 00320 grind 264sf intake dur.264 exhaust dur 270. at .050 intake 230 exhaust 236. lift int. 458 exhaust 468 lobe sep.is 112. this is a solid lift cam that will be very mild in my sbc. it will be in my street car (81 bu). what a lot people forget is that a street car (mine included) spends 80 percent of the time under 3000 rpm. i did not think that it was true until i watched my tach. for hours when i would go out for a cruise. sure i would nail it a lot because i live in the country but the 80 percent rule was true for me.yes i use the dish pistons. q-jets were very misunderstood but are great carbs for the street. i'm hoping for good torque for a short burst up to 5500 rpm. and 3:73 gears.
glad to hear from you again motorheadmike. that was a very good combination 355 in my opinion. i have heard and seen very good results with the type of build your 355 was and mid 12's is just great. my machine shop guy said to watch out for some of the used vortec heads as they were prone to cracks but not all of them so just beware. double drilled i thought was strange too but there it was. i watched for vortec's for a while but i would also have to go vortec intake and i have a bunch of regular intakes i wanted to try out. as stated before the pro comps remind me of the early world products street replacements (st) my nephew used years ago. when i raced my 70 bb chevelle i used merlin vr's and hooker slipfit wrap around headers. one of the headed tubes rubbed right against my starter so i bought a mini starter and that did not help at all. i then cut and rerouted that tube away from the starter and had my nephew tig them back together.life was good after that. i know there some big block guys out there that ran the same combination and had the same problem so lets hear from you. hooker 2 1/8 tubes slip wrap around were fun to work with in the stock engine bay. add some header wrap and changing spark plugs was fun. btw my nephew and myself ran Dart aluminum on his 70 nova. he watched me suffer with the wrap arounds and went with regular headers. i try to buy american but it's very hard to do nowadays. maybe this new administration in the w.h. will change that. i will try to keep you posted on this bucket list build. thanks for listing to my rant. Denny
Sorry Denny if we sound a little hash. In my daily job I decide what flies and what goes into the trash bin so we are all brutally honest.
I'm sure you can make those heads work, but there are probably easier/better options for your combination that don't have the downsides of those heads.
I think you can easily surpass your goal of 300 HP with your motor and those heads. There are potential downsides that you should be aware of and since we aren't trying to sell you anything, we can be honest about those downsides.
I'm sure you can make those heads work, but there are probably easier/better options for your combination that don't have the downsides of those heads.
I think you can easily surpass your goal of 300 HP with your motor and those heads. There are potential downsides that you should be aware of and since we aren't trying to sell you anything, we can be honest about those downsides.
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