I finally got my heads machined and flow tested after getting the budget porting only with no sanding rolls or polishing. No fancy valve job just regular 3 angle stuff. $170 Ebay stainless 2.07/1.71 valves . Very pleased to hit my flow goals and know my Rallye 350 will run decent and have a chance. Just didn't want nor could accept the stock small valve heads as is being such a air flow bottleneck. So here ya go
.100" 65/54
.200" 135/109
.300" 201/144
.400" 225/164
.500" 237/177
.600" 242/181

 

Nicely done.
I have done the same to my small block, except mine are fully ported.
Never had a chance to flow them.

 

Thanks, I look forward to getting it together this Fall and on the drag strip this winter

 

I figured big valve small block heads would hit the old Edelbrock/Procomp flow numbers. I figure mine aren't far off those numbers, hope adding w 2.07" with the bowl opened up vs the current 2" with see a nice gain for the 425 SBO future build.

 

So far my cost in these heads are $100 at the machine shop for cutting to big valves and valve job, surfacing (guides were ok) , $200 porting at http://elliottsportworks.com/?page_id=9 , $170 for valves (Ebay-free shipping) , I did buy Crane Olds screw in studs and some guideplates also and some Ford style 1.7 cheap roller tip rockers but all that is external to the heads and transferable to anything else. I do still need to buy my springs and retainers locks which will be coming soon.

 

Sounds great , I'd love to build up one of mine like that but also be able to run Ac , good flow heads and maybe not so big a cam and I can do it?

 

I am very much looking forward to seeing what the stock mild QB 286/286 .472 cam in my 4 speed will do with this head mod and the 3.91's. Only other mod is the ratio making it about .500" plus the zero lash manual adjustments so it can rev good. Later down the road after testing this stock 286 cam and stock appearing setup (manifolds and 2.5" mandrel bent good pipes) a swap to either an old Dual Energy Comp 275 DEH (219/233 110) or maybe a custom Howards (221/235 110 or 112) would be my preferred combo to maximize power with manifolds and maintain better low-mid torque than a W31 setup IMO

 

This engine still yet to be installed but dang it , this year is the goal now.

 

Those are really nice flow numbers for those 350 heads. Very interested to see it finished and what it runs down the 1/4 mile.

 

Thanks, I am excited at the potential. Especially since I decide to run headers on the Rallye to compliment flow and intake plenum mods and port matching. It should fly !


Also I did end up scoring a new in box cam cheap I can track test against the OEM 286 cam down the road. It is a Comp XE268-10 224/230 110 its about the size I was going after and $30 well there ya go

 

What compression is this motor? It should really fly with that bigger Comp cam, tough to beat for $30. What valve springs are you running. Looking at your flow charts, you hit the stock heads flow at .300 and gained 30 cfm intake and exhaust at .500 lift over stock heads. I know most say the 1.625" exhaust is better, curious if there would have been a gain over the 1.71 exhaust valve.

 

older set of new TRW (Speed pro) 6 cc forged replacement for the 68-70 310 hp engine but I don't recall if I measured deck height say 9.5-9.7 #6 heads not milled just surfaced really that I know so lets say 68 cc . I think the 1.625 versus the 1.68-1.71 is same flow with same port work just not any better is what others said. Springs are Herbert performance 1.437 110# seat @ 1.75 using about 060 worth of shims if I recall and 10 degree titanium retainers http://www.herbertcams.com/hers084tk...etainer-combo/

 

Yes the 1.625 exhaust is more than adequate for a small block.
And if you want to regain or retain low end tq, both of your next cam choices are wrong. You need something much closer to a single pattern. You’ve got way too much on the exhaust side.

 

Mark, those two big split profiles I mentioned two and half years ago when I was planning on running manifolds for stock appearance on my 3.91 geared 14" tire car for best mid range and upper rpm power with manifolds. I have since decided on running headers after scoring new Hookers cheap and to not hamper the otherwise good head flow and my current OEM 286 straight profile cam to run initially will be followed by comparing and testing the 6 degree split new XE 268 grind I got very cheap recently. As far as loosing low end maybe but it my car the rev's will be up most of the time regardless considering the drive line gearing. ALthough apples to oranges in the past my friends have had very strong running street cars with 350 SBC running the old Comp 275 DEH even when good head flow balance existed and headers too. One was a flat top 355 swapped to stock vortec 1.94 1.5 valve heads that only had a spring upgrade and valve job in a 4 speed muncie 4 door 57 chevy with 3.73 gears and he got a 12.8 in the 1/4 out of it. with say a 8.2 eighth. Same engine went into a 79 Malibu wagon budget drag car with automatic and went down to a 7.6 . Others with Trick flow heads and that cam ran similar times. Noted I am not disagreeing a loss could hurt on other cars with stock highway gears sure.

 

Here it is 3 years later and I just finally port matched my intake yesterday. Long block has been assembled for about two years and also the frame still off the car that long as well. I will be testing this engine in my wagon I guess after all. Don't like stuff sitting that long. Maybe the Rallye will go together next year

 

Don't worry. I been building my current small block for almost 6 years lol. Its got run time on the stand but I found some rocker arm clearance issues ( hitting the poly locks). Fixing that then should be good. Car has been down all year ( sold the last engine ) trying to maybe get it out in the fall for some shake down runs. Its a budget build but lots of horse trading and bartering and trading labor was involved lol. I think 11.70's is realistic.

 

I look forward very much seeing your car keep hitting the new goals. Great job ! I am about to pull the "mule" 350 out of the wagon this weekend. Its assumed "the position" yesterday. The "Good" 350 for the Rallye 4 spd in the wagon will get the headers and a 2500 12" stall. Thinking it may do some solid 13's with the 3.08's in the wag. I did meet my goal of busting into the 11's in my 63 Catalina this year on a 255/60 drag radial with the same engine that was in the wagon two years ago. That was in hot weather too so my Fall it should see mid 11's with no real changes. I did swap to a oldWarrior intake though to help shift my torque peak higher and better match the converter. For the record though I have ran 7.5 in the 1/8 with both the cast iron one and the Warrior though.

 

Well here it is 9.5 years later after heads were ported and this year finally the 030 350 with these heads will go in the car intended and I ended up scoring a NOS Wolverine W31 blueprint cam so it will be getting a single pattern after all and a good match to the car anyway with the 3.91 rear so we shall see how it does eventually

 

Great to hear an update.

 

Thanks and yep a year ago just finally got the painted frame under it and got it out of it's tomb and back into Active project status LOL

 

very nice
LLOYD does awesome portwork, i live close to him and he did manh heads for me already.
I am thinking about giving him my 403 ,#4 heads instead of chasing 350 heads and or go for speedmasters.
with the approach of doing the #4 heads I don't have to worry about intakes or head bolt holes,
+ with any set I get I have to invest in some work anyways.

 

Hey man just so you know Lloyd no longer does any work on iron heads ! Only aluminum now. He was actually having health problems from it and has gotten better since. His father had a similar thing when he did them for many years. I just found out a few months ago when I got a intake ported. He has moved to SW of Red Oak (Oak Leaf) from his old place to the East of there

 

Looks good.
But just an fyi for all, the move to the 1.71 vs the 1.68 exhaust valve really does nothing to improve flow. The problem is the port, not the valve size. Waste of time and money. Just sayin.

 

good info, thanks for sharing

 

What part of TX are you in?

 

me?
DFW

 

Thank's Mark, I am aware of that from when this post was done back 9 years ago and wasn't looking for max hence I didn't even pay him for the polish part just a rough cut quick port back then but also what minutia between 1.71 and 1.68 , thats how the valves came on Ebay as a set anyway 2.07/1.71 full set , bump valve on the grinder is gone the .03" lol

 

Ennis

 

get the new SBO Edelbrock Gen III heads for your 403 its perfect and keep the stock 403 dish piston, or go true flat tops on 403 and buy the BBO Gen III Edelbrocks in the larger chamber and you did not share what your 403 is insatalled in so if its a Trans Am I understand the use of Performer RPM matched to BBO gasket is a shaker issue but they do sell the extra drop base lower air cleaner to offset that