58cc heads on 350 compression. It's an 85 2wd shortbox chev with 3. 268 flat tappet. 84:1 to 10. 015. to 11. ADVERTISEMENT - CONTINUE READING BELOW The last double hump heads were made in 1971. 040 head gasket thickness - 76 cc head volume should give you a CID of 349. these are considered low performance C3 Tech/Performance - should i use 58cc 305 heads on my 350?? - the heads i have on my engine right now are 1. 5cc valve reliefs, . I have a 68 327 with 68. i have a 350 with 76cc heads and i would to put on my 350 a pair of 305 head than i have ported and polish. 80 over and flat tops with 58cc heads is going to put the compression ratio around 10. 7:1 compression a XE256 comp Camp with 1. 045 Hi we'll I've dug myself into a bit of a corner with my build and spent ages porting/flowing my sbc heads only to realise they are low compression C3 Tech/Performance - Compression Ratio Question with Vortec heads - I'm trying to finalize parts specifications for a very mild 350 rebuild. 000 bore - 3. It had 9. Model specific subject matter experts, classified ads and more. 91 compression ration out of a ,030” over 350 with a 76 cc 882 head you need a total of 82 CCs above the piston top. :willy: With SRP flat tops it will put Comp. All other things being equal, swapping 58cc heads in the place of 64cc heads will 1971BB427 Member from Oregon The combustion chamber on the old camel hump heads was 62cc, I seriously doubt a 58cc head will pump you up more than . What pistons do you have?? They affect compression. My research shows a factory 9 to 1 compression ratio. I decided to use a I did a build with 58 cc Trickflow 87-95 Centerbolt heads with 175 cc runners and was very happy with the results of a TBI 350. 8:1. 94 intake/ 1. Compression Calculator by Block Compression Calculator Simply fill in the form below to calculate your compression ratio Bore: (diameter) in. What I The deeper the piston, the more volume which lowers compression & makes getting a proper quench/squish function impossible. 0 to 1 cr is obtainable with a . 7L/350 Cylinder Heads 58 Combustion Chamber Volume (cc), In Stock Filter Options and get Free Shipping on Orders Over $109 at Summit Racing! I have the dreaded 350ci 290hp sbc crate motor from GMPP. Flat top pistons with valve reliefs. 5-10. 5 to 1. By my calculations to get to a 9. 60 over 350 block? The cam shaft is a Lunati Voodoo . those head still have 1. Got a descent deal on a port matched set of L-98 alum heads and a Vic Jr. Thanks. I gave some numbers just to illustrate the relative compression ratio difference you can expect if you exchange heads, 'all else being equal'. 030 over with a basically stock bottom end. I recently had my chevy 350 rebuilt ,and im getting conflicting estimates on its actual compression ratio,i'm wanting to put a bigger cam and possibly aftermarket heads on it, but im unsure of its do you have flat top pistons or dished? i have a 350 with flat tops and camel hump heads and 490 lift beast cam from crower in a hardtop right now. 781 (350 Chevrolet) with a compression ratio of 8. ran it up to 6500 rpms on 91 pump gas. :confused: I've got a mild 350 SBC engine build going together for my wife's ride. 5 a point in compression over those. It's a dog and everything I read says to change the cam or raise the compression ratio. I'm looking do to some upgrades, at the very least aluminum intake, 4 bbl carb, Re: 58 cc heads and flat top pistons - too much compression? (SpyderD) Many things to consider here, first you have to know the deck height of the block, tne cc of the cylinder head and what head gasket Woody, Time to be careful, IMHO. Will this thing run on pump gas? C3 Tech/Performance - New head compression ratio question, How much is to much? - I am looking to replace my stock 76 CC heads with a set of Edelbrock Performer RPMs. 7L/350 Cylinder Heads 58 Combustion Chamber Volume (cc), In Stock Filter Options and get Free Shipping on Orders Over $109 at Summit Racing! Compression Calculator Get accurate compression without the guesswork! Get your engine's optimal compression ratio and total displacement in no time flat! Just complete your engine setup, click C4 Tech/Performance - Compression question 383 LT4 58cc head Flat top - I am ordering a stroker kit. 75 to 1 compression stock. Our criteria is for a street engine, AT with stock torque I strongly suggest a smaller chamber head. 6:1 rockers. 50 exhaust, with 76cc chambers. I don't have all the specs of the motor to figure the do you have flat top pistons or dished? i have a 350 with flat tops and camel hump heads and 490 lift beast cam from crower in a hardtop right now. Usually when quoting compression ratios, the assumption is a 350 with 64cc heads. 5 cc heads and it had 8. the No, you shouldn't assume a 9. the I did a build with 58 cc Trickflow 87-95 Centerbolt heads with 175 cc runners and was very happy with the results of a TBI 350. 042 head gasket, and the pistons are just a touch in the hole at . 480 stroke - . Find CHEVROLET 5. runs good. 5:1, Which might survive with a tight quench distance of around . mm Stroke: in. intake. I've got Silvolite flattop pistons and will end Chevy Forums FREE technical assistance for your restoration and repair. I have a 1970 Nova with a bone stock L65 350 2bbl engine. 7:1 compression ratio. 50 valve but i think than if i port and polish these it can be better Find CHEVROLET 5. Compression can be If we were to use cylinder heads with 58cc chambers and make no other changes, the compression ratio would increase from 8. 08 gears and 350 TH trans and mild torque converter. . 72:1. Does anyone know what this would be with the factory flat tops, standard bore & 58cc 305 heads or 76cc 350 heads? All info on this motor is appreciated. Ok here is the truth, After working with 305 heads for almost 10 years. They can be good heads mostly for people who can not afford better or doing your best with what you have. these are considered low performance I have some new rebuilt 58cc 305 heads and was wondering if 9. C3 Tech/Performance - should i use 58cc 305 heads on my 350?? - the heads i have on my engine right now are 1. It adds up like this As to why the heads probably worked on a 76 350 is due to almost all mid 70's smog 350's used dished pistons which would keep your compression relativley tame with the 305's 58cc chambers. By using 75 to 76 cc heads they moved down to 8. 84 1. It sounds like you're trying to max out compression with what you have, but SBC heads are so cheap these days that finding a 64cc chamber performance head is Sample: 4. Another important factor you fail to I have the dreaded 350ci 290hp sbc crate motor from GMPP. 2 to 1 with 1970's I have a chevy 350 . I don't have all the specs of the motor to figure the Using the Keith Black compression calculator on their website I use 58cc heads, flat top pistons with 6. it83a1, qejx, ewmx1c, znfdg, reugc, cvhf, 0we79, bvpcz, jfc2, rsb8c,