I have one of the window main 350's,and I have a set of 3a and a set of 5a heads. Would the 5a heads work on the 350, its basicly stock low compression with .030 over bore and a 214/224 .474 int. .498 ext. 112* cam. I just have the cast iron intake from the 307, but I do have headers. I have put the chevy 305 on the chevy 350 with no problems at all. Could the olds be done the same way, I just looking for a little more compression, this should work.
Heads
- Thread starter 87oldssalon302sbc
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They will bolt on and give you a little more compression, but I dont know how they flow compared to the 3A heads.
Im sure some one who knows more info will help.
Im sure some one who knows more info will help.
Heads with numbers on them are small block heads. Heads with just letters on them are big block heads. What is the casting number of the 5a heads if you get me that i can even tell you the valve size if you want that then i can tell you what head is better 5a or 3a i gotta look it up in my book.
they made both 5a and 3as at two different time so i could use the the casting numbers for both heads.
I have 5A heads on 76 350 Olds along with the small port Edelbrock SP2P intake. I used the thinner Corteco gaskets, I would use them over felpro(.028 vs .039) and the 204/214 .448/.472 cam. The intake limits top end, but helps part throttle and economy. I have this in my 94 chevy 4x4 Z71 with a 3.73 open :shock: rear and tall 265/75R16 tires. I also have Sanderson shorties and 2 1/4" duals with an h pipe. With it's limited stock TBI setup, base timing set at 8 degrees and has a questionable fuel pump. It has more oil pressure, runs cooler and will easily keep up with my brother in law's 2004 5.3 powered Avalanche. Both heads have nearly identical terrible exhaust ports. The 3A has a better flowing intake but are crack prone. The 5A will give better quench and better velocity but that cam is too big for either heads. Either early 330 or 350 heads will flow better with 64-70 cc chambers. The 307 head is either 64 or 67 cc, didn't cc mine. The 3A has 75cc chambers.
Not looking for top end, both sets need to be rebuilt, just wanting to build a daily driver, but I like to have the muscle sound. would the comp. 268 H be a better choice, I think its spec's are 218/218 .456 int. .456 ext. on 110* lsa. I have either cam, as far as I know both sound the same, with a little lope.
If you have the comp cam lying there than use it. Olds like split pattern, short duration, high lift cams, and most comps are not. Get a good 3 angle valve job done to the 5A heads, mill them .010-.020 and maybe get them to use a bowl hog and pocket port them. Use the larger 1.875 intake and 1.56 exhaust valve won't hurt either. Those valves can be found cheap and will help flow too. Top them off with .028 Corteco gaskets if you are not 0 decking it.
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