So I've come to a fork in the road with my 77 Camaro project. My best friend is getting a Chevy Monza that has a running 305/th350 combo that he plans on replacing with a 406/5spd combo. I have a 307 Chevy that I've been working on for a while. Would it be worth buying the 305, sticking my big (for a 5L) cam in it, and start saving for a bigger badder engine?
Short answer: No.
Long answer: The 307 has a larger bore (it's a 283 with a 327 crank, the 305 has a 350 stroke crank) so there's less valve shrouding. Even if you don't take advantage of the larger bore with bigger valves, the larger bore will translate to better flow through the head.
editation: I am assuming that you already have a running 307. If you are still looking at most of a 307 hobbykit, are planning on upgrading beyond that at some point, and you're being offered an engine that will allow you to get your car on the road now, then the only thing I can say against the idea is that swapping engines is a bunch of work. I don't know how hot you are to get your car mobile, though.
Well at the moment the 307 is torn apart on an engine stand in my kitchen. The car doesnt have one. But the 305/th350 combo won't cost me very much. I don't have a transmission atm either. I bought the car in December as a roller and have been working on it since trying to get body work done and floor pans in it.
If he's asking not too much, go 305/350. Bet that turd rolling, man. Nothing will kill a project quicker than loosing interest. (Says the guy with a dead P71 project on permanent back burner.
He won't ask very much. I know what he paid for the car. I have to finish some body work issues that I ran out of money on (college and a truck payment does that). Then I'll have that bad boy on the road.
If you can fit it in your budget, it sounds like a cheap way to get a trans and maybe some extra parts to sell later. Also weren't 305 heads on a 350 a thing for about five minutes back in the 80s? Higher compression maybe? Not the greatest heads obviously but i they're even marginally better than yours for what you have in mind it might be worth mixing and matching the engines together. If not just keep it as a running back up as stated above.
Stock for stock, there isn't much difference, but big cam plus 305's tiny bores = big ugly mismatch. No low end, no top end, and 7 mpg.
You can buy a running 350 these days for $250 and have more power than you would with either 305 or 307, plus it will be much more tolerant of upgrades.
The combo should come well in under budget. And I was thinking drop the 305 in for now with my cam I bought for the 307 a while back (SUM-1105) then when I get the short block together on the 307 just swap the heads off and run it until I get the money for a 406
If you like autos (because you're Bob Costas, 
) I would just buy the Th350.
I think, depending on the vintage of 305, that if you rebuild and bolt on the 307 heads you get a smaller combustion chamber, thereby more compression. Costly part is I'd bet the 307 heads won't have hardened seats.
The heads that came on my 307 have bigger combustion chambers than any head that came on a 305. In fact before this deal came up I was looking for a set of 305 heads to bump the compression way up.
In reply to Mr_Clutch42:
I'm wanting to keep this car a small block, small tire, automatic car. I've got plans for a bolt action later on. A big block, big tire, bolt action
DCharger68 wrote: The heads that came on my 307 have bigger combustion chambers than any head that came on a 305. In fact before this deal came up I was looking for a set of 305 heads to bump the compression way up.
I'm not sure what you are trying to accomplish, but you are taking parts from GM's smallest-bore family and trying to make power. I promise you (after countless years in the hotrodding business) that you will spend multiple times more money on gaskets than you would just buying a 350. Seriously. 350s are a dime a dozen, and with a very tiny amount of money you will make way more torque and power than with the money you spent on a 305 or 307.
I'm serious. You can hop-up a 307 for $900 and have a 250-hp pile of iron that no one will ever buy, respect, or appreciate... or you could buy a bone-stock 350 for $200 and have a 250-hp pile of iron that is ready for 500 hp with $500... and then be able to sell it for $750.
Where are these running 350's for that cheap? They have been $400 cores around here for years..
I did score myself a 355 with KB hypereutectic flat tops, Crane Fireball cam, and 305 heads with 1.94 valves and bigger valvespings for $500 a couple of weeks ago.. my plan is to put better valvesprings on the vortec heads that are on the 305 in my Camaro and put them on the 355 and put it in my Camaro and make tons of tire smoke.. then I will put the 305 heads on the Camaro's old 305 and put that in my 3/4 ton GMC pickup in place of the tired 307 that's been in it since 2002..
So I guess I'm saying to look for a rebuilt 350 from someone's abandoned project and get it cheaper and don't screw around with a 307..
The only real advantage of the 305 is if it's available to slip into the car in a weekend and get rolling. Driving a slow car is better than not driving at all.
There is a 8l vortec big block in a yard near me for 3-400. So why even waste cash on small block when the goal is big.
If I were in your shoes I'd buy the 305/TH350 from said buddy and drop it in the Camaro as is just to get it back on the road. While it's running on turd power I'd sort out the brakes, chassis and suspension in accordance with your plans.
This conversation has brought back old memories from when I used to play, "What size Chev can we build?" 307 block is a 3 7/8 bore, 305 has a 3.48 stroke, which is a non-factory combination. So, trying to remember volume of a cylinder...A set of custom pistons would build you a 329. Overbore .030, and its a 333. Always a fun game.
Incidentally, and more to the original point of the story, you are a 4" block away from a 327 using 307 reciprocating parts.
In reply to Streetwiseguy:
Yeah I know. If I had the budget to allow for 327 internals, I'd find a 4" bore block. Unfortunately my budget allows for either the 307 I bought in high school, or the running 305 my friend is getting.I'd love a 327 just for the availability of parts and the fact nobody uses them.
DCharger68 wrote: In reply to Streetwiseguy: Yeah I know. If I had the budget to allow for 327 internals, I'd find a 4" bore block. Unfortunately my budget allows for either the 307 I bought in high school, or the running 305 my friend is getting.I'd love a 327 just for the availability of parts and the fact nobody uses them.
you have 327 internals... just need a set of pistons..
novaderrik wrote:DCharger68 wrote: In reply to Streetwiseguy: Yeah I know. If I had the budget to allow for 327 internals, I'd find a 4" bore block. Unfortunately my budget allows for either the 307 I bought in high school, or the running 305 my friend is getting.I'd love a 327 just for the availability of parts and the fact nobody uses them.you have 327 internals... just need a set of pistons..
I was thinking forged pistons and rods. But you have a point.
Stock chevy rods are all forged. The "good" pink rods from the late 60's Corvettes and Z 28s just had an extra magnafluxing step... just put some ARP bolts in them and get them resized.
Hypereutectic pistons are good to 500ish hp if you keep it from detonating.
Ok, this is "Dad" advice, but at least it is motorhead dad advice. Take the Monza 305/TH350, drop it into your car and make it a runner. Ideally, don't even mess with cams, intakes, etc., just get it installed and running.
This way you will at least have a running/driving 77 Camaro. I'm not saying to lose sight of your dream of having an 11 second car, but having the lump run and drive will stave off a lot of project ennui and prevent you from losing interest. Plus it's just a lot more practical to drive the car in and out of the garage, onto and off of trailers, etc. than it is to push or pull it. Trust me, I have winched my share of cars onto trailers with come-alongs and it gets old.
And my final bit of advice, and this comes from someone in the middle of two 2nd gen F-body projects, is to remove the front end from the car to do the engine swap. The front end of these is so long that even with the boom on your hoist at the farthest extension it will be a major pain to maneuver with the front end on.
SEADave wrote: Ok, this is "Dad" advice, but at least it is motorhead dad advice. Take the Monza 305/TH350, drop it into your car and make it a runner. Ideally, don't even mess with cams, intakes, etc., just get it installed and running. This way you will at least have a running/driving 77 Camaro. I'm not saying to lose sight of your dream of having an 11 second car, but having the lump run and drive will stave off a lot of project ennui and prevent you from losing interest. Plus it's just a lot more practical to drive the car in and out of the garage, onto and off of trailers, etc. than it is to push or pull it. Trust me, I have winched my share of cars onto trailers with come-alongs and it gets old. And my final bit of advice, and this comes from someone in the middle of two 2nd gen F-body projects, is to remove the front end from the car to do the engine swap. The front end of the car is so long that even with the boom on your hoist at the farthest extension it will be a major pain to maneuver with the front end on.
That sounds like a plan. I've gotta pull the front end off anyway to put floor pans in and clean up the subframe.
curtis73 wrote: 350s are a dime a dozen
Prove it.
The last one was made, what, 10 years ago? 15? You can find a GOOD LSx in a pull-a-part type yard easier than a 350. Eliminate the LT1s and derivatives and anything with Vortec heads (need a comparatively rare aftermarket intake to run a carb) and where are we? 20 years? 25? All the rebuildable 350s got snatched up around here years ago. You might find a smokey one running in a rust bucket truck for $800 and be able to scrap the truck for $300, but that's as close as you'll get.
novaderrik wrote: Where are these running 350's for that cheap? They have been $400 cores around here for years.. I did score myself a 355 with KB hypereutectic flat tops, Crane Fireball cam, and 305 heads with 1.94 valves and bigger valvespings for $500 a couple of weeks ago.. my plan is to put better valvesprings on the vortec heads that are on the 305 in my Camaro and put them on the 355 and put it in my Camaro and make tons of tire smoke.. then I will put the 305 heads on the Camaro's old 305 and put that in my 3/4 ton GMC pickup in place of the tired 307 that's been in it since 2002.. So I guess I'm saying to look for a rebuilt 350 from someone's abandoned project and get it cheaper and don't screw around with a 307..
Do this if you can. As noted its very rare to find such a deal but it does happen.
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