|02-28-2007 05:12 PM|
a well prepared 400 CI engine, they will outperform the Vortec heads if
both are unported.
In addition the edelbrock heads make a good race head for mild applications
when ported correctly. I have ported many sets with very good results.
Times at the drag strip in the low 11 to mid ten second range with a flat
top 355 and a solid flat tappet cam w/3200 LBS car.
The springs are set up with 120 LBS on the seat for 320 lbs at 0.500" *.
Check with the camshaft manufacturer, I personally have never had a problem
losing a cam lobe with these springs.
* RPM Instructions
|02-28-2007 12:03 PM|
I appreciate all the advice.
AFR also mentioned a 4 to 6 week waiting list for a set of 180s or 195s.
Ive already got the short block assembled. I wasnt too thrilled about letting it sit partially assembled for a month or more so I decided on the Edelbrock performer RPM's.
I read an article in Chevy High Performance, it is also available online.
Can I expect similar torque numbers with the Edelbrock heads instead of Vortecs? Are the springs on the performer RPM heads too stiff for breaking in a Comp 270H flat tappet cam?
|02-27-2007 10:14 PM|
All are good heads.
To get the edelbrock heads to flow near the AFRs they will need porting.
Both edelbrock castings are near identical 170cc intake ports, the RPMs
have stiffer springs for higher RPM.
The AFR 195s are a good choice for a light weight street car or for racing,
not ideal for a 4000 LB truck but will work.
The AFR 210s are a good choice for a race engine, defiantly not for a
4000 LB truck.
So if I were you I'd go all out and get the AFR 180s or save a few bucks
and get the edelbrocks.
|02-27-2007 10:01 PM|
I VOTE WITH DEUCE.
Personally I think AFR are tops.
|02-27-2007 02:22 PM|
|MIKE FROM SM||I like the AFRs better. They have thicker decks and the castings are nicer. I think most AFRs are partially CNC ported too.|
|02-27-2007 01:20 PM|
The truck has 3.73 gears and the factory torque converter.
I also considered Edelbrock Performer or possibly Performer RPM cylinder heads. Theyre cheaper then the AFR heads and I imagine they too will make good power. Anyone have any experience with these?
|02-27-2007 12:11 PM|
|MIKE FROM SM||If you have a low enough gear and a loose converter, I would go with the 195cc. Otherwise go with the small heads. A heavy vehicle with big heads will be a dog.|
|02-27-2007 11:54 AM|
Why would you consider someone you never met ... ( like a internet backyard mechanic guy ) over the pros @ AFR ??
I would go with what they recommended ... they are the pros and they want to be HAPPY with their product ... so they will recommend the BEST option ...
Or at least that has been my experience ...
Your experiences may vary
Deuce ... Forum Moderator
|02-27-2007 11:46 AM|
|techinspector1||I don't think port volume tells the whole story. Look at the puny little ports in a L31 Vortec head, 170 cc's, but they flow like they're much bigger.|
|02-27-2007 10:52 AM|
SBC 400 cylinder head question
Im assembling a 400 small block chevy that will see action in a street driven 4000+ pound chevrolet pickup.
The short block is already finished, the cam is a a comp 270H (.470 lift and 224 duration intake and exhaust) and compression with a 65cc cylinder head will be 10.4:1 on paper, not actually measured out because I do not have the heads.
I called AFR and asked for their reccomendation. I was considering the 210cc Race Ready cylinder heads. They are not perfect for my setup but I wanted to buy something I can use down the road in a higher horsepower application. AFR reccomended their 180cc street head. The 195cc street head would also work I was told, but the 180cc would be ideal.
Is a 210cc head that mis-matched for my application? Has anyone run an set of AFR heads and been pleased/displeased with the results?