akdale

Been a while since I have asked any advice.
SBC 355 CID, 9.5/1 compression (too high I know) current heads Edelbrock performer 2.02/1.6, 185 ccc intake runner, 64cc. I did not design the motor and it's still in good shape so I figure rather than another rebuild an upgrade to heads will yield a better solution, better flow and will provide great results. Cam specs: Dur @.050 233/234 Lift 488/510 112 Sep. I am looking a AFR and DART heads. Curious on which ones? I need to get my compression down to 8.0 or 8.5 area. I have methanol injection and a MSD programmable pulling timing but i am overdriving the little 142 to the max (10 PSI, get about 8) hence AV gas. it's still on the bleeding edge of detonation at times I am sure. So there you have it. Any thoughts, real world examples of your build. Thanks for any assist.

gkull

10 psi basically brings you into the 500 hp range so you need the best heads to support that. AFR makes 75cc heads and Dart makes 72cc Dart pro 1 heads can be bought with bigger valves. So a Dart 215cc can be bought with 2.08 and 1.60. AFR 210 cc might be a good choice with 2.08 or the 220cc heads with 2.10 intakes.

509 rat

What's your initial timing set at and what's your total timing all in also you should have all your timing in at 2500 rpm if you can program your curve, this from what I have gathered from several competent blower people .Here's my set up .

akdale

Nice! MSD locked at 32 with 1degree per lb of boost after 4lbs. Its all in at 2300.

509 rat

My motor is a l 82 4 bolt main 350 I believe its 9 to 1 compression dart pro 1 aluminum heads shorty headers 1 5/8 headers , I am changing out the headers to 1 7/8 I have msd 6 btl I am still messing with it but it fires right up and runs good the only thing I have not done yet is the light all in 2500 rpm distributor springs, did that make a big difference .The motor was in the car when I bought it and when I blow it up I will build a dart shp block with a scat crank and rods double keyed crank like a 434 stroker .I am running 10 pounds of boost with race gas .

76strokervette

If you have access to e85 you can make what you have work with some fuel system changes

cv67

A Case of Torco Accelerator is about 120-130 ought to last you awhile
Either brand head are fine...I have real nice set of heads that would be perfect for that app...except the CC may be too small.

Gale Banks 80'

On a street driven car You might be better off with the 9.5 Compression. You need to balance what kind of power your making just off idle and what Your doing when at full boost . On a street driven Turbocharged car I made the mistake of using the " Correct " 7.8 to one Compression and around town the car couldn't get out of its own way till it started making Boost. For me that was 90 percent of the driving. I realize that a Blower Motor will make Boost quicker that a Turbo so it shouldn't be as apparent. I would keep track of your diving habits and what sort of Boost pressure You have when doing it. And plan on all the time You have very low Boost your going to loose power with less compression. Take any mid 70's 350 with 8 to one compression and add duel carbs with 1000 + CFM to it. Now when its idling snap he Carbs wide open and watch it fall on its face. That's what I would be concerned about.

akdale

I was thinking about that. So tonight I put the 3.25 inch top pulley on (dropped boost to 6lbs) and played with my timing curve a little. Still scoots along pretty good. This is on 91 octane with 1 can of royal purple octane boost. I am going to leave it this way for now and continue researching my cyl head path

akdale

My local Ford Dealer is the only place to get it. Pricing it out Monday.

509 rat

I agree on what your saying I am running 2 quick fuel blower carbs 650 cfm to keep the throttle response snappy at lower rpm where most of my driving will be .

509 rat

Is it easy to change out the timing curve springs and can you do it with distributor in motor , it looks like a pain in the *** right now I have the heaviest springs all in by 5500 rpm and I am wanting to put the lightest springs all in by 2500 rpm which most are saying to do I would think that having a lighter spring will speed up the throttle on accel and deceleration if that makes any sense . .

stingr69

I get Torco on Amazon. I only need it when I can't get good 93 octane gas for my blown LS3.

cv67

Joel aka jbsblownc5 is a dealer here on the forum if you need a backup source.

akdale

Easier here with my 6530 programmable ignition, 5 min on the laptop

akdale

They wont ship it to Alaska

Gale Banks 80'

I didn't realize Your location. So not to much city driving to contend with. Although I live in Seattle I work out of Dutch Harbor where I currently am for the summer.

509 rat

I should have bought that but I figured that once its dialed in I would not need it but wish I did now .

509 rat

Does anybody have a idea what spark plugs are best some are saying the n NJK r5671a-7 are good but what heat range should I be at from what I am hearing 2 heat cycles cooler than stock and what is the stock heat range .thanks guys not trying to hijack thread but I think its all related .

509 rat

oh ya what gap for plugs .