jmarksdragster

:lol: :lol: :lol: Thanks!! Seems like a lot more than that, I sent the heads castings to Curtis/RFD in August 08, hit the dyno the first of October. It has been good so far, first race down to 3 cars, runner up the second and won the Citrus the third. It will be a tough act to follow next season. The 461 is definitely not an easy build, nothing on top fits right. But so far worth the effort.

rdy2fly

Hi, thanks for the advise, so you are saying that the 421 will be more durable. What kind of hp, tq numbers can I expect. I do plan on going with 210 AFR heads and a solid roller 248/256@50 with a 672 lift Int./Ext.

poboyracin

I think you have a good plan with the 421 (I just built one too for pump gas) but you could stand a little more head on it. Take a look at the new Profiler 220cc CNC heads by Dr J's Performance and Speier Racing Heads called the "Air Wolf". http://www.j-performance.com/index.p...d=44&Itemid=61

bjuice

If your gonna go all motor (Stroker) i would go ahead and Purchase the 18 degree set up...saw a many 18 dergee 434ci (HIGH WINDING STUFF) turning 9,000rpm that would get it done.....it may be a little more up front fore the 18 degree stuff but for the performance difference it will be worth it in the long haul...

if you build the right 18 degree 421/434...you gonna be very surprised how it runs compared to the 350ci



Good luck

rdy2fly

If I choose to go 18 degree, who's head do I go with? Keeping in mind that this is a streetable car. Would you still go with the 18 degree stuff? Does anyone have a good set of 18 degree heads for sale? I'm told that with this 3180 lb car I will never hook it up with this engine. I hope,I can prove them wrong.

poboyracin

If you have the budget to go 18 degree, or even less degree... That would be good but I don't think it's needed in a street car with the cam you're running. You'll never see the full potential. Plus, you'll need shaft rockers, off-set lifters, matching pistons, etc...

If this was a high rpm, (8000+) high compression, (15:1+) huge roller cammed engine, (280 @.050"+) I'd say you needed 18 degree or better heads...

Brodix make an 18X degree head that uses standard valve train but it doesn't flow but what the CNC 220cc 23 degree head flows.

Just my opinion...

bjuice

Dart,Brodix any of those manufactures can set you up on the 18 degree set up..piston's heads, valve train...
I know you are Getting Opinions...so let me expand mine a little more.

i saw where you said Street and Some track time...Here is My thoughts..even tho you couldn't flat foot the 18 degree engine on the street...your not gonna be able to do it in a well built 23 degree 434ci either.
You might as well build what you can get Now and Grow into later...i have never seen a hot rodder that didn't want more....and if you chose the 23 degree stuff now and could have spent a little more to get the 18 degree stuff.......then you are gonna be real sick when you see what it will cost to go BACK TO A 18 DEGREE MOTOR ...

Go ahead and do it right the 1st time.....

I done been there done that........if you worried about having too much power on the street somtime strip...then KEEP WHAT YOU HAVE and sell the New SHP block you got coming.

2nd don't go trying to buy someones used up junk when it comes to heads etc....unless you know your stuff what you looking at, you can get burned here very easy.

if you are gonna have the engine Built i can refer you to PAR racing engines that will set you up at a great price and parts etc..


Just My opinion.


thanks

rdy2fly

I am on a budget guy's, I have 7600 bucks for this project. I am not worried about to much hp for the street but rather reliable and durable performance. What can I get out of a 421 with good 23 degree heads? My goal is 650 hp plus 550 to 600 ft lb tq. I hope my goals are attainable.
Should I sell the shp block and go 350 and blower, will this give me plenty of low end torque.

DRTRCR22

Just MY opinion Fly... KEEP the Dart block, and stick with 23* setup...!

Once you have a Dart or World block, there is no logical reason to ever go back to a stock GM block. Get a severe duty rotating assembly as big as what can reasonably fit inside this Dart SHP block, and go with the blower on 23* top end. The blower will give you the kick in the pants you are looking for. Since you are on a budget, the 18* setup will take everything you got right up front... (just my opinion, as I have only investigated the outrageous costs, and have never bought or built anything other than 23* before).

Jim

poboyracin

I think you'll need at least 12.5:1 compression, somewhere around mid 260 - low 270 duration at .050", near .700 lift camshaft, and heads flowing around 320 CFM to reach those goals. No matter what degree head you go with...

650hp will go 10.0's or possible 9's in a well set up car at your weight.


11:1 compression, 260 @.050" solid roller with .650 lift, and good 23* heads with matching intake would net right around 600hp and show it at the track. It will be pump gas and street friendly if set up right.