305 Question

[t5montecarlo]

I am going to say no, because you need the heads from a 305G. The El Camino only came with a 305H. The G and H are the engine ID in the VIN.

 

[deanz406]

I've been playing with 305's for quite a few years, mostly with some of the local stock car guys that have to run a 305 in the "Pure Stock" class. There are quite a few combinations that will work well. The most common 305 heads are casting #'s-- 555-434-450-416-601--- and the newer centerbolt heads with #'s 081- 187. Just to clarify some of the numbers-- the 555 casting was used on the very first 305's from 1975-1977, small valve(1.72 X 1.40)-- the 081, and 187 are newer style centerbolt heads, with the 081 having a completely open intake port, and the 187 having the swirl port. Another rather rare casting made in the mid 90's was the 059 casting, and was used exclusively on the 305 Vortec motor, commonly used in pickup trucks. Although they also have a 1.84 X1.50 valve, they can be opened up to a 1.94 X 1.60. They also have a swirl port, but not as profound as the 187 casting. The drawback on these heads is the intake bolt patterns. The 434, and the 450 were later(1978-1982), but were really lightweight castings and most had the 1.72 intake valves, although I have seen a couple 450's with a 1.84 intake. These were VERY prone to cracking, especially in the center where the 2 exh valves are. The 4416, and 601 are the best of the bunch, each having a 1.84 intake. The 416 had decent flow numbers, commonly around 165 CFM, and the 601 usually around 162-163. The comb chamber in the 416 is usually 60 cc, while the 601 is 56-58cc. Like Andy at D&A Machine said, the 601 can be a really hot setup, especially if u open the intakes to 1.94, and exh to 1.60. If u do opt for the 416, or 601, and decide to put a 1.94 in it, it's best to have the chamber unshrouded for clearance around both valves, for good flow results. I have done a couple sets of these, with the big valves, and doing a full competition port job, with excellent results, and some pretty good flow numbers.
I have a 305 built with full flat top pistons, a set of the 601 heads(fully prepped), a comp solid cam- 504 in/ 498 ex-- 248*in/ 254* ex, came out to 11.5-1 comp ratio, Edel RPM Air Gap, 780 Holley-Vac, MSD ign, 1" 5/8 Hooker comp headers, and it dyno'ed 418 HP at 6500 RPM. I have it in a 3200# Regal, TCI 4000 conv, 4:10 gears, and it runs 12.50's all day. It is so easy to make some decent HP numbers, and the Monte SS, and the Camaro Z-28 w/ the 305 HO were rated at 205 HP for a start. You could up that HP, with a RV type cam, a good dual plane intake, headers, and a 600-650 DP carb, good ign, and be around 250-275 HP. This would be the cheapest way to get the HP u are looking for. I have just completed a 334 S/B (305 w/ 400 crank), bored .030, flat top pistons, with same solid cam, 350 Vortec ported heads, Edel RPM Air Gap intake, 750 Holley DP, and will be putting it in the same Regal, and hoping for the low 12's. I think the 305 is a really fun motor to play with, and I'm always looking to build LITTLE motors that GO FAST. Well, Good Luck with ur project-- plan carefully, select the right parts, and you will have a fun ride-- Dean 8)

 

[NOT A TA]

I had a 78 Malibu I bought from a guy that ran low 13's at the track with it. He stopped going because he blew a rocker arm off twice using stock heads. Turned out he had an aftermarket cam and valve spring setup that was walking the rocker arm studs out of the head enough to mess them up. I took the heads to a machine shop and had the studs pinned which cured the problem. Ran great after that, then life happened and I had to sell it.

 

[80montecarlo]

I've been playing with 305's for quite a few years, mostly with some of the local stock car guys that have to run a 305 in the "Pure Stock" class. There are quite a few combinations that will work well. The most common 305 heads are casting #'s-- 555-434-450-416-601--- and the newer centerbolt heads with #'s 081- 187. Just to clarify some of the numbers-- the 555 casting was used on the very first 305's from 1975-1977, small valve(1.72 X 1.40)-- the 081, and 187 are newer style centerbolt heads, with the 081 having a completely open intake port, and the 187 having the swirl port. Another rather rare casting made in the mid 90's was the 059 casting, and was used exclusively on the 305 Vortec motor, commonly used in pickup trucks. Although they also have a 1.84 X1.50 valve, they can be opened up to a 1.94 X 1.60. They also have a swirl port, but not as profound as the 187 casting. The drawback on these heads is the intake bolt patterns. The 434, and the 450 were later(1978-1982), but were really lightweight castings and most had the 1.72 intake valves, although I have seen a couple 450's with a 1.84 intake. These were VERY prone to cracking, especially in the center where the 2 exh valves are. The 4416, and 601 are the best of the bunch, each having a 1.84 intake. The 416 had decent flow numbers, commonly around 165 CFM, and the 601 usually around 162-163. The comb chamber in the 416 is usually 60 cc, while the 601 is 56-58cc. Like Andy at D&A Machine said, the 601 can be a really hot setup, especially if u open the intakes to 1.94, and exh to 1.60. If u do opt for the 416, or 601, and decide to put a 1.94 in it, it's best to have the chamber unshrouded for clearance around both valves, for good flow results. I have done a couple sets of these, with the big valves, and doing a full competition port job, with excellent results, and some pretty good flow numbers.
I have a 305 built with full flat top pistons, a set of the 601 heads(fully prepped), a comp solid cam- 504 in/ 498 ex-- 248*in/ 254* ex, came out to 11.5-1 comp ratio, Edel RPM Air Gap, 780 Holley-Vac, MSD ign, 1" 5/8 Hooker comp headers, and it dyno'ed 418 HP at 6500 RPM. I have it in a 3200# Regal, TCI 4000 conv, 4:10 gears, and it runs 12.50's all day. It is so easy to make some decent HP numbers, and the Monte SS, and the Camaro Z-28 w/ the 305 HO were rated at 205 HP for a start. You could up that HP, with a RV type cam, a good dual plane intake, headers, and a 600-650 DP carb, good ign, and be around 250-275 HP. This would be the cheapest way to get the HP u are looking for. I have just completed a 334 S/B (305 w/ 400 crank), bored .030, flat top pistons, with same solid cam, 350 Vortec ported heads, Edel RPM Air Gap intake, 750 Holley DP, and will be putting it in the same Regal, and hoping for the low 12's. I think the 305 is a really fun motor to play with, and I'm always looking to build LITTLE motors that GO FAST. Well, Good Luck with ur project-- plan carefully, select the right parts, and you will have a fun ride-- Dean 8)

I would love a little more info on that 418hp 305, make things tingle all over hearing those kinda #'s. Wouldn't mind having my 305 pull somewhere in that hp range and ET's for this upcoming season, if I ever get my curse_sign.gif @$$ in gear and work on my car

 

[deanz406]

80montecarlo-- to answer some of ur questions on my 305 build. I tried to pay attention to detail, and did a lot of research on available variable 305 components, and a selection of parts that would work well together. I kinda designed it around how fast I wanted to make my car go, driveability, easy maintenance, but did take into consideration having to use a mix of fuel (40/60-- 2 gal 110 VP to 3 gal 93), because of compression, although some guys say 1 gal of 110 would be sufficient. I picked a Comp cams solid cam, their Nostalgia series tight lash, which I told in the previous reply. The cam had a 112 L/C, which helped with idle quality, but I did advance it 2* to bring the power band down a little. It's a tight lash solid with valve lash at .012in/.012 ex. I liked the 601 casting which had a pretty tight chamber at 56-58 cc. I did a lot of work to them, including a full competition port job, had pedestals machined for studs & guideplates, opened valves to 1.94in, and 1.6 exh, and had machine shop unshroud the chambers. I had them cut .026, and ended up with a 53cc chamber. My block had a .032 piston to deck, and didn't want to spend the extra on decking. I tried to do this on a fairly reasonable budget. I had it bored .030, and I used a Speed pro hypereutectic full flat top piston, which had a little more material on the crown than KB, or Ohio piston, and used the GM steel .016 head gasket. C/R came in at 11.5/1. I lightened the GM pink rods,and sent the rotating assy out for balance. I used an Edel RPM Air Gap dual plane intake, MSD ign, 750 Holley D.P., 1" open spacer, Harland Sharp 1.6 roller rockers, and Hooker 1 5/8 Comp headers. I had the 350 turbo maxed out at my trans shop, and have a TCI 4000 stall converter, and have 4:10 gears, with a 26 X 10 slick.
I noticed some of ur engine specs, and they are quite different than mine, but works well for what u are using, and u have a decent time at 13.10. You noted that u had a 461 head-- was that a typo error, because the 461 head is a 60's 327 head with 64 cc chambers. I think u meant 416, which is also a good head, but has a 60 cc chamber. I think you can make a lot more torque if you switched to the RPM Air Gap intake, and went to a solid cam, you would notice a substantial HP gain. The hydraulic cam ur using is much smaller than mine. I think u mentioned ur heads were ported, but u didn't mention whether u had them cut, and cc'd.
That's about the extent of my 305 build, so if I forgot anything, please ask. You only have to make a couple subtle changes to ur existing setup, and u should make mid 12's easy. Remember, pay attention to detail, and selection of parts, and have outstanding machine work done. I have a top notch machinist here in my town, and his work is impeccable. Dean 8)

 

[deanz406]

80montecarlo-- I just went back to the beginning of the article and looked at ur specs again-- I saw in one u have listed a 3:73 gear, and in the latest one, u have 4:56 gears. I see u listed a 650 D.P., and ur converter is completely inadequate. The converter alone would make a huge difference, and with the 4:56's, a solid cam, Air Gap, and a 750 D.P. carb, you can easily shift around 6200-6400, and click off some low 12's easily. Dean 8)

 

[80montecarlo]

80montecarlo-- I just went back to the beginning of the article and looked at ur specs again-- I saw in one u have listed a 3:73 gear, and in the latest one, u have 4:56 gears. I see u listed a 650 D.P., and ur converter is completely inadequate. The converter alone would make a huge difference, and with the 4:56's, a solid cam, Air Gap, and a 750 D.P. carb, you can easily shift around 6200-6400, and click off some low 12's easily. Dean 8)

deanz406 what do you recomend for a converter, I have a 750DP in the box waiting for my old man but i will just take it back, manifold I was leaning towards a Vic Jr., Yes my heads have a heavy(not full tilt) port job on the heads I did them myself and I am still learning, raised the roof of the exhaust and cleaned up the ports to a gasket matched, blended bowls. Heads have been decked 0.050" on the 416's, the block is still standard deck height, If I remember right I have -0.037" to the piston at TDC, 0* initial advance on the cam. and my pistons are if I remember right are -15cc. 1.94" intake (unshrouded, heads are coming off anyways so I am going to do that this month and some other touch ups) and 1.50" exhaust. Can I get some more specs on that cam from you?

 

[Damon]

Just about every 305 4bbl engine from 80-81 on up had 416 heads. The low output LG4 and the high output L69 used the same heads. Differences between them was the compression (pistons- dished vs. flattop), cam, exhaust and tuning. If you find just about any 305 with a a computer controlled QJet 4bbl on it, it's got the good-guy -416 heads. The later 87-88 heads were -081 castings and they were basically the same head with centerbolt valve covers and the oddball 87-up intake bolt pattern.

Flattop pistons, a mild Summit K1102 or K1103 cam kit, entry level dual plane intake and some shorty header + duals (even little 2-1/4" duals are fine) will hit your goal with ease. Most of the parts are transferrable to a larger 350 later, obviously.

 

[deanz406]

80montecarlo-- I would recommend at least a 3500 stall converter-- I chose the TCI that I'm using, because of some of it's features, I wanted it streetable, without a lot of rpm to move the car. I wanted one with a anti-ballooning plate, so i could use it with a larger engine, later on another build. It was advertised at 3500-3800 Rpm stall. I tested mine, and it flashed at 3700, which worked well. The part # is- TCI-241002. It is the one advertised with the anti-ballooning plate for nitrous use. The regular 10" didn't have the plate.
I chose the Comp Cam " Nostalgia Plus" cam, P/N 12-673-4, because of it's specs. Adv dur- In,284*- Ex,291*-- @.050, In,247*- Ex,254*-- Lift- In, .504-- Ex, .498---- 112* L/C-- Lash, In,.012-- Ex, .012. This is a tight lash cam, which is my personal preference on a lot of the solids that I use. Your cam, although a hydraulic is fairly close, with Adv dur- In, 284*- Ex.296*-- @.050, In,240*- Ex,246*-- Lift-In, .507- Ex, .510-- and on a 110* L/C. Your cam advertised with a 2300-6500 power band, and my cam is 2300-6900. I chose the 112* L/C because it gives me a little more leeway on my piston/valve clearance, as i advanced my cam +4* to move the power band down a few hundred RPM. I also use 1.6 rockers to give me more lift, and that helped the torque also. If u want to make serious power, I'd definitely opt to look at some of the solid cams. Since the 305 is kinda a small cu.in motor, the key to really decent performance would be to get away from the single plane intakes, and definitely go with the dual plane Air Gap-- It will make gobs more torque, and that's what moves weight. The 750 D.P. should work well, right out of the box, but do yourself a favor, and custom tune it to ur motor. I got away from using power valves, and square jet all my carbs. I jetted my carb with #77, front and rear, squirters, 31F- 31R, pink pump cams, 30cc pumps, front & rear.
That's about it for the specs u asked for, remember, unless u build it exactly like I did, with exactly the type of parts that I used, your outcome may be a whole lot different. Keep in touch, and let me know how u are progressing-- Best of luck-- Dean 8)