The best part about being poor is that you know you're sure what you want to do after about two years of hemming and hawing over parts. So with that said, I think I've made my decision, and as always, appreciate the forums opinions (good or bad).

I just picked the block up from the machine shop and they had to bore it out .030. I'm dead set on not stroking it, so if thats your opinion, throw it out the window please.

Here's the info:
010 4-bolt block bored .030
using stock crank, rods & flywheel, to be internally balanced
Speed Pro forged 3.4cc pistons
Brodix IK180 64 cc heads
Three deuce intake system: Offenhauser intake w/ Rochester 2g carbs
Hooker Super Comp 1 3/4" headers
ST10 close ratio tranny
3.55 rear gears
Compression ≈ 10.0:1 depending on head gasket

Now I wanted to go with the XR276HR Comp Cam, but I figured with the duration (224/230) it would give me too much overlap with a 110° LSA. The lift on it is .502/.510. Does anyone else think this is too big and I should step down to the XR270HR or am I just right?

Also, Brodix "recommends' fel pro's 1003 head gasket, which is .041" thick and would give me a 9.9:1 SCR. I was honestly hoping to bump this up above 10:1. Would it be a problem going thinner?

The goal was 400HP with more low to midrange power (a reason I'm considering the XR270HR).

Whatcha think!?!

 

Sounds like it will be fun!

But a couple of questions...
Why are you dead set against stroking? Is it just the added cost? (I'm not trying to convince you otherwise, just wondering.)
Why do you really want to get over 10:1? 9.9 or 10.0 has no practical difference... But anyway, if you wanted to get higher compression and use the 'correct' gasket, have you looked at domed pistons or milling the heads? (or just buying 58cc heads?)

 

Stroking is an added cost, and while it is alot more practical than a tripower set up (which is solely for looks and nostalgia), I'm fine with a 355. The heads are only available in 64cc, so I would have to mill, which I think is just another added cost whereas I could get a thinner head gasket and get there at the same price.

 

I like the whole set up, I would go bigger cam like a 230/236 and might as well go roller, now compression just use a thinner gasket like 039 thick

 

XR276HR IS roller. But I agree, it doesn't sound like a bad combo.

God bless, Sensei

 

Oh yeah, I read that thought it was a flat tappet,, anyway still a nice set up..

 

Looks like a pretty good combo. However, for your 355, I suspect you should go with the 1 5/8" headers. Othrwise you'll be giving up too much low rpm torque.

 

Really... I was wondering about that, could you elaborate? I'll admit as far as headers, I thought this was one piece that usually follows the rule "bigger is better." As long as you don't get into wave tuning, I thought it was best to get back pressure low as possible.

 

You have to look at how big your heads exhaust ports are. I bought my H S/C 1 3/4 twenty years ago and they still work pretty good.

Minor compression gains are very marginal to power gains

You can use a bigger roller cam @.050 than H-flat and it will still run nice.

buy the billet steel sleeved cam instead of a pot metal cam. Crane sells some nice street rollers with 112 lobe centers The 230/238 might be a good choice

 

Don't mill heads.

Deck the block about 0.015" so pistons end up about 0.010" down in hole ... use GM gasket 10105117 or 14096405 (both = 5.8cc x 0.028") or Victor Reinz 5746 (5.4cc x 0.026") ... all 3 are composite & suited for use w/ alum. That is dual purpose approach ... optimizing quench while increasing scr.

If you have numbers-match block ... ensure shop will deck without cutting ID pad.

FYI ... all Erson sbc roller cams are billet steel & all come with friendly gear & often have nice price. Similarly ... GMPP has 2 or 3 rollers worth considering.

 

I like your first cam choice along with 1-5/8 headers

 

Are Erson cams still available? Erson seemed to disappear a while back.

 

I'll look into it, thanks gkull. I just don't wanna add too much duration because I'm trying to keep my power band somewhat low, this is a steet only application.

The machine shop could not guarantee that they wouldn't remove the VIN if they decked. I could easily use those GM gaskets and get above 10:1, and this wont' cost me any extra $$$.

I've never heard of Erson cams, nor can I find them on google. You got a link jackson?

 

Bigger tubes dont necessarily mean less backpressure.
Header tubes that are correctly sized for your engine will help to scavenge exhaust gasses out of the cylinder.
If you go to too large of a primary tube, you lose the vacumming effect. So even though the pipe is larger, less exhaust gets out of the cylinder .

 

Very true, thanks for pointing that out.

 

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AFAIK ... erson bought merged w/ pbm a year or 2 back ... afaik still in carson city NV